ASTM F1778-97(2020)
(Guide)Standard Guide for Selection of Skimmers for Oil-Spill Response
Standard Guide for Selection of Skimmers for Oil-Spill Response
SIGNIFICANCE AND USE
4.1 This guide is intended to facilitate the oil spill response equipment selection process for local, regional, and national spill response teams. It is not intended to define rigid sets of equipment standards.
4.2 The effectiveness of the equipment chosen to combat an oil spill will depend on the oil type and environment(s) encountered, as well as other factors. This guide is intended to be used by persons generally familiar with the practical aspects of oil spill cleanup operations including on-scene response coordinators, planners, oil spill management teams, oil spill removal organizations, and plan evaluators.
4.3 Eleven general types of skimming systems are described in this guide. Each description includes a summary of the operating principle and a list of selection considerations.
4.4 Selection considerations are included to guide the user on the selection of a particular skimmer type or category. Users are cautioned that within each category there may be a wide variation in performance among various skimmers.
4.5 When selecting a skimmer for use in extremely cold conditions, consideration should be given to the effect of ice forming on the skimmer, changes in buoyancy, possible restriction of inlets, and changes to hydraulic efficiency. Because there may be wide variations in skimmer performance at extreme temperatures, even within a given category, ambient temperature is not included as a selection consideration.
SCOPE
1.1 This guide covers considerations for selecting skimmer systems for the recovery of marine-oil spills. The purpose of this guide is to provide oil spill response planners, equipment manufacturers, users, and government agencies with a standard on the equipment selection process for the removal of oil from the marine environment.
1.2 This guide does not address the compatibility of spill-control equipment with spill products. It is the user's responsibility to ensure that any equipment selected is compatible with anticipated products and conditions.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F1778 − 97 (Reapproved 2020)
Standard Guide for
Selection of Skimmers for Oil-Spill Response
This standard is issued under the fixed designation F1778; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This guide covers considerations for selecting skimmer 3.1 Definitions:
systems for the recovery of marine-oil spills. The purpose of
3.1.1 encounter rate—the volume of oil per unit time
this guide is to provide oil spill response planners, equipment
actively directed to the removal mechanism. F631
manufacturers, users, and government agencies with a standard
3.1.2 nameplate recovery rate—the maximum skimming
on the equipment selection process for the removal of oil from
capacity of a device under optimum conditions of oil type,
the marine environment.
slick conditions, and environmental conditions.
1.2 This guide does not address the compatibility of spill-
3.1.3 oil recovery rate—the volume of oil recovered by the
control equipment with spill products. It is the user’s respon-
device per unit time. F631
sibility to ensure that any equipment selected is compatible
3.1.4 recovery effıciency—the ratio, expressed as a
with anticipated products and conditions.
percentage, of the volume of oil recovered to the volume of
1.3 The values stated in SI units are to be regarded as
total fluids recovered. F631
standard. No other units of measurement are included in this
3.1.5 throughput effıciency—the ratio, expressed as a
standard.
percentage, of the volume of oil recovered to the volume of oil
1.4 This standard does not purport to address all of the
encountered. F631
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Significance and Use
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 4.1 This guide is intended to facilitate the oil spill response
1.5 This international standard was developed in accor- equipment selection process for local, regional, and national
dance with internationally recognized principles on standard- spill response teams. It is not intended to define rigid sets of
ization established in the Decision on Principles for the equipment standards.
Development of International Standards, Guides and Recom-
4.2 The effectiveness of the equipment chosen to combat an
mendations issued by the World Trade Organization Technical
oil spill will depend on the oil type and environment(s)
Barriers to Trade (TBT) Committee.
encountered, as well as other factors. This guide is intended to
be used by persons generally familiar with the practical aspects
2. Referenced Documents
of oil spill cleanup operations including on-scene response
2.1 ASTM Standards: coordinators, planners, oil spill management teams, oil spill
F625 Practice for ClassifyingWater Bodies for Spill Control removal organizations, and plan evaluators.
Systems
4.3 Elevengeneraltypesofskimmingsystemsaredescribed
F631 Guide for Collecting Skimmer Performance Data in
in this guide. Each description includes a summary of the
Controlled Environments
operating principle and a list of selection considerations.
4.4 Selection considerations are included to guide the user
ontheselectionofaparticularskimmertypeorcategory.Users
This guide is under the jurisdiction of ASTM Committee F20 on Hazardous
are cautioned that within each category there may be a wide
Substances and Oil Spill Response and is the direct responsibility of Subcommittee
F20.12 on Removal. variation in performance among various skimmers.
Current edition approved April 1, 2020. Published April 2020. Originally
4.5 When selecting a skimmer for use in extremely cold
approved in 1997. Last previous edition approved in 2016 as F1778 – 97 (2016).
DOI: 10.1520/F1778-97R20.
conditions, consideration should be given to the effect of ice
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
formingontheskimmer,changesinbuoyancy,possiblerestric-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
tion of inlets, and changes to hydraulic efficiency. Because
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. there may be wide variations in skimmer performance at
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1778 − 97 (2020)
extreme temperatures, even within a given category, ambient 5.3.1 Oil Type and Viscosity—Few skimming principles
temperature is not included as a selection consideration. operate with optimum effectiveness over a wide range of oil
viscosities. For many skimmers, recovery rates will tend to be
5. Skimmer Selection Considerations
less than the reported maximum rates for oils that have a very
lowviscosity,andforoilsthathaveaveryhighviscosity,either
5.1 Selecting a type of skimmer for a given application
initially or as a result of weathering or emulsification, or both.
involves examining the skimmer’s likely performance against
On the other hand, several skimming principles such as brush,
a range of operational requirements. The following are recom-
drum, and paddle-belt skimmers operate most effectively with
mended as a guide to this process, with the requirements
more viscous oils.
grouped according to the operating environment, the slick
5.3.1.1 Recommended viscosities for skimmer performance
conditions, and skimmer performance criteria. Comments on
data are given in Guide F631. These include: 200, 2000, and
each of these operational requirements, specific to each skim-
60 000 mm /s. These values are referred to in the skimmer
ming type, are given in Section 6.
selection considerations as low, medium, and high viscosity
5.2 Operating Environment:
oil.
5.2.1 Wave Conditions—Depending on the type of skimmer,
5.3.2 Slick Thickness—Slick thickness greatly affects the
waves may affect both the oil-recovery rate and the oil-
recovery rate of virtually all skimming principles, nameplate
recovery efficiency. In general, most skimmers work best in
recovery rates only being achieved with thick slicks. Slick
calm conditions with decreases in recovery rate and efficiency
thicknessalsoaffectstherecoveryefficiencyofmostskimmers,
as waves increase; in particular most skimmers are greatly
in particular those employing suction or weir skimming prin-
affected by short choppy waves. For each skimming type,
ciples. On the other hand, many skimmers can deal effectively
comments are given on the sensitivity to different wave
with thin slicks by varying the operating parameters of the
environments. (Classification information for calm, protected,
device (that is, for oleophilic devices, by reducing the speed of
and open-water environments is given in Practice F625.)
the oleophilic element, and by adjusting the weir settings for
5.2.1.1 Additionalconsiderationsforselectingskimmersfor
weir devices).
particular wave conditions are that both the skimming device
5.3.2.1 In evaluating a skimming principle based on ex-
andtherequiredsupportplatformareapplicabletotheintended
pected slick thickness, consideration should be given to
environment.
whether containment booms can be used to concentrate oil for
5.2.2 Currents—Should the operating environment of con-
recovery.
cern have significant water currents, this should be considered
5.3.2.2 In the skimmer descriptions in Section 6, reference
in the selection process. Many skimmers will not operate
is made to device performance in thin slicks, which is defined
effectively in currents greater than 1 knot due to decreases in
as continuous slicks less than 1 mm in thickness, or discon-
throughput efficiency. On the other hand, several skimming
tinuous patches of oil with an average thickness of less than 1
principles such as the sorbent belt, brush, submersion plane,
mm.
advancing weir, and boom skimmers rely on relative current
5.3.3 Debris—The presence of debris presents two concerns
for effective operation and are applicable in currents greater
in a skimming operation: first; that debris may restrict flow to
than1knot.Severalskimmertypessuchastheoleophilicbrush
the skimming head, and second, that debris may interfere
andoleophilicropemopareavailableaswell,inconfigurations
directly with the skimming component (that is, clogging or
that allow them to operate effectively in high currents.
obstructing openings, impeding moving parts). Some skim-
5.2.2.1 Comments on performance in currents are restricted
ming types, such as most oleophilic devices, are largely
tothosedirectlyrelatedtotheskimmingdevice.Ifcontainment
insensitive to the presence of debris. Suction and air conveyor
booms are used to collect or concentrate oil, or both, for
devices are generally tolerant of debris up to the size of the
skimming, additional operating limitations related to contain-
transfer hoses used.Weir devices, in general, are susceptible to
ment boom performance in currents may also apply.
clogging with debris; however, many weir devices use integral
5.2.3 Water Depths—Water depths may be a concern for
transfer pumps that can process a range of debris types. Where
skimming operations in nearshore waters and when supporting
applicable, comments are made on debris tolerance or sensi-
a shoreline cleanup operation. It is important to note that any
tivity in the selection considerations comments. It should be
draft limitations would apply to both the skimming device as
noted that these comments pertain to the general skimming
well as the required support vessel; certain skimmer types,
type, and that certain skimmers within a given category may
although not requiring deep water for their skimming
include means of dealing with debris. Guidance for a range of
component, may require large support vessels for deployment
debris types respecting skimmer performance can be taken
and operation.
from Guide F631, which lists a number of debris forms for
5.2.3.1 While many skimming types are available in a range
skimmer testing.
of sizes that may allow their operation in shallow waters,
certain types are generally applicable to shallow water depths
5.4 Performance Requirements:
and these are noted in the skimmer descriptions. Skimmer
5.4.1 Recovery Rate—For some applications the most im-
types in this category include rope mop skimmers, vacuum
portant performance criteria will be the product recovery rate.
systems,airconveyors,someweirskimmers,andsomesorbent
Although the various skimming categories are available in a
belt skimmers.
range of sizes and capacities, generalizations can be made on
5.3 Slick Conditions: expected recovery rates. In this guide, comments are made on
F1778 − 97 (2020)
expectedrecoveryratesonlyastheywouldapplytothevarious 6.2.1 Description—Boom skimmers include any device in
skimming principles and not to particular devices. For which the skimmer is incorporated in the face of the contain-
example, weir skimmers and boom skimmers are available ment boom, regardless of the skimmer type. This system can
with high nameplate recovery rates, limited only by the include a single skimmer installed in the face of the boom, but
available pumping capacity. On the other hand, oleophilic in many examples of this concept there are several skimmers
skimmers tend to have a fixed upper limit of recovery used. In most boom skimmers, weir-type skimmers are used.
depending on the size of the oleophilic surface used (that is, Boomskimmersprovideacombinedcontainmentandrecovery
surface area of discs, length and diameter of rope mop). system.
6.2.1.1 Oil spill containment boom is often attached to each
5.4.1.1 Although specific skimmer performance data are not
side of the mouth of a skimmer in order to increase the sweep
included in this guide, users are reminded that a skimmer’s
width. Although such a system would be similar to a boom
nameplate recovery rate should be used with caution as it may
skimmer, it would not meet the definition of a boom skimmer
not accurately reflect skimmer performance under varying
because the skimmer in the system could be used apart from
conditions of slick thickness, slick viscosity, and environmen-
the boom. In a boom skimmer, the skimmer is part of the boom
tal parameters. Where possible, performance data based on
and is not intended to be used by itself.
field use or experiments should be used, with reference to the
6.2.2 Selection Considerations:
slick and environmental conditions of particular concern to the
6.2.2.1 Oil Type—Applicable to low and medium viscosity
user.
oils.
5.4.2 Recovery Effıciency—Selection of a skimmer based on
6.2.2.2 Debris Tolerance—Debris must be screened or re-
the expected recovery efficiency may be particularly important
moved from the skimmer opening.
depending upon the availability of storage, the availability of
6.2.2.3 Wave Conditions—Recovery rate and efficiency de-
systems to separate free water from the recovered fluids, and
graded by choppy waves.
thepermissibilityofdischargingdecantedwaterattherecovery
6.2.2.4 Currents—May be operated at currents greater than
site. The expected recovery efficiency will, for most skimming
one knot, at reduced recovery efficiency, by pumping at a high
categories, vary greatly depending on the thickness and vis-
rate.
cosity of the slick and on the environmental conditions at the
6.2.2.5 Water Depth—Generally limited by towing vessels.
spill site.
6.2.2.6 Mode of Application—Requires relative forward ve-
5.4.2.1 In general, skimmers using oleophilic principles can
locity: may be operated in stationary mode if current present.
be expected to have higher recovery efficiencies relative to
6.2.2.7 Other—Typicallydesignedforvessel-of-opportunity
skimmers using weir or suction principles. Among weir
application.
skimmers, devices in the induced flow category can be ex-
pected to have a high efficiency. As well, several skimming
6.3 Brush Skimmers:
categories are typically configured with onboard gravity
6.3.1 Description—Brush skimmers are oleophilic skim-
separation, which would enhance their overall efficiency. For
mers that pick up oil on the bristles of a brush. There are two
skimmers without onboard separation, oil/water separation
main configurations for the brushes: drum brush skimmers, in
shou
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