December 20091 Standardization for Oil Water Separator (OWS) and Oil Content Monitor (OCM) Systems In-Service Engineering Agent Perspective December 2009

December 2009 1

Standardization for Oil Water Separator (OWS) and Oil Content Monitor (OCM) Systems In-Service Engineering Agent Perspective

December 2009Presented to: ASTM F25 Environmental Seminar

Presented by: Ray A. Morales US NAVY (NSWCCD)

December 2009 2

In-Service Engineering Agent Responsibilities

• Provide technical support to the fleet for the in-service Oil Pollution Abatement (OPA) system including OWS, OCM, and transfer system.

– Test and Evaluation– Equipment Modifications– Technical Assistance– System Certification and Training

• Provide support for the acquisition programs– Design and Specification reviews

Standardization for Oil Water Separator (OWS) and Oil Content Monitor (OCM) Systems

December 2009 3

Applicable Standards & Regulations for Navy OWS and OCM systems

• Navy Ships are considered public vessels– Department of Defense (DOD 4715.6-R1)– Office of Chief of Naval Operations Instruction (OPNAVINST 5090.1C)– American Bureau of Shipping (ABS) Naval Vessel Rules (NVR) – USCG (Title 46 CFR Part 162.050 - Pollution Prevention Equipment)– International Maritime Organization (IMO) ( MEPC.107(49) )

• ASTM Standard– ASTM F2283 “Standard Specification for Shipboard Oil Pollution

Abatement System”• Provides general design requirements• Refers to MEPC.107(49) for OWS and OCM requirements.


December 2009 4

Challenges for OWS and OCM systems• Performance issues

• Reliability

• Maintenance costs

• Obsolescence issues

• Capital costs of unique systems

• Lack of Standards to ensure performance, reliability, and maintainability


December 2009 5

Testing of MEPC. 107(49) Certified COTS OCMs

Objective

To conduct laboratory testing of selected IMO MEPC 107(49) certified COTS OCMs to evaluate their performance under various operating conditions and in the presence of contaminants to determine if these units would be suitable for shipboard use in Navy vessels based on direct comparison with the in-service OCM unit.

Case Study –

Testing of Commercial off-the-Shelf (COTS) MEPC. 107(49) Certified Oil Content Monitors (OCMs)

6

Test Set-up


WATER PUMP

OIL INJECTION SYRINGE PUMP

DISPERSER

WATER PURIFICATION

THERMO SCANNER

DATA ACQUISITION

DRAIN FUNNEL

Sediment Pre-filter

5 Micron Filter

0.5 Micron Filter

TAP WATER FEED

FLOW METER

PRESSURE GAUGE / TRANSDUCER

SAMPLE VALVE

AIR PUMP

PRESSURE RELIEF VALVE

P

P

CONTAMINANT INJECTION

SYRINGE PUMP

WATER FEED TANK

PRESSURE GAUGE

CONTAMINANT TANK

RECIRCULATION PUMP

WATERHEATER

December 2009

7

Screen shot of data acquisition software


December 2009

8

Testing Performed

• Pre-test Checks:– General checks to determine installation/ interface requirements and to ensure that OCM and testing

equipment are operational• Calibration Test:

– To verify OCM calibration at 0 PPM, 15 PPM and maximum oil concentration that the OCM can measure• Oil Droplet Size Distribution Test:

– To determine deviations of the OCM calibration due to variations in oil droplet size distribution• Flow/Pressure Range Test

– To determine deviations of the OCM calibration within the design Flow rate and Pressure Ratings and to determine if the OCM is fail-safe beyond the design flow/pressure range.

• Temperature Range Test– To determine deviations of the OCM calibration within the design temperature Range.

• Different Oil Types Test– To determine deviations of the OCM calibration in the presence of different types of oils (i.e., the oil mix#

components separately; DFM, 9250, 2190, JP-5 and Synthetic oil) • Response Time Test

– To determine time required by the OCM to alarm once high oil content is present. • Contaminant / Interferences Tests (color, air, solids, emulsions, salinity) – Decision

Making Test– To incrementally change each given parameter to determine at which point: (1) The OCM measurements

are affected and (2) The OCM decisions are affected (i.e., allows overboard discharge or recycle to the oily waste holding tank)


December 2009

9

Conclusions drawn from this testing• The COTS OCMs tested failed to detect free oil, failed to accurately measure oil under the conditions expected in the effluent of a failing OWS treatment system and required highly mechanically dispersed oil for accurate measurements.

• The COTS units tested produced critical failures (would allow overboard discharge of > 15PPM oil-in water), with and without interferences/contaminants, when tested under the conditions expected from a failing OWS treatment system .

• COTS units tested did not accurately measured different types of oils (affected calibration)

• Then COTS units tested required significant routine maintenance to keep operating properly. The sampling cell of the COTS units were cleaned between tests to ensure a zero baseline and prevent drift in the readings.

• Response time results were not consistent with requirement (e.g., < 5 secs)

• COTS units tested did not provide for “Fail-safe” design: – Continued operation even with no flow allowing “by-passing” the OCM while the data recorded shows

acceptable effluent. This could allow continued operation of OWS even with unacceptable overboard discharge while zero (0) oil PPM is recorded.

– Design does ensure diverter valve default position to recycle during all possible failures modes

• COTS units tested were designed and calibrated to meet MEPC.107(49)


December 2009

10

Test Results/ FindingsOil Droplet Size Distribution Test (Disperser’s settings)

Droplet size distributions at various disperser's speeds

0

20

40

60

80

100

120

0 10 20 30 40 50 60 70 80

Droplet diameter, um

Cu

mu

lati

ve %

oil

dro

ple

ts 6,000 RPM (Min)

8,000 RPM (Std)

10,000 RPM

12,000 RPM

14,000 RPM

16,000 RPM

18,000 RPM

20,000 RPM

22,000 RPM

23,00 RPM (Max)

Testing of Commercial off-the-Shelf (COTS) Oil Content Monitors (OCMs)

December 2009

11

Test Results/ FindingsOil Droplet Size Distribution Test (Disperser’s settings)

Oil Droplets Micrographs: 15 PPM oil injection at 8,000 RPM Disperser’s Speed (Standard Conditions)


46µm

28µm

25µm

6µm28µm

6µm

4µm3µm

32µm

29µm

6µm

6µm

35µm

28µm

8µm 3µm2µm

14µm

5µm

13µm

12µm

13µm

5µm14µm

9µm

6µm

32µm 5µm

3µm

December 2009

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Test Results/ Findings Oil Droplet Size Distribution Test

Sample Conditioning Test at 15 PPM Oil Injection

0

5

10

15

20

25

0 6000 12000 18000 24000

Disperser's Speed (RPM)

Oil

Co

nce

ntr

atio

n

(PP

M)

Navy OCM 1 OCM 2 OCM 3


December 2009

13

Test Results/ Findings


Different Types of Oils Test

0

5

10

15

20

25

bilge mix diesel fuelmarine

2190 lube oil 9250 lube oil JP5 synthetic

Different Types of Oils

Oil

Co

nce

ntr

atio

n, P

PM

v

ET-35N OCM 1 @ 8k RPM OCM 1 @ 12K RPMOCM 2 @ 8k RPM OCM 2 @ 20k RPM OCM 3 @ 8k RPMOCM 3 @ 22K RPM

December 2009

14

Test Results/ FindingsResponse time


Response Time, Secs(at 40 PPM oil Injection)

31

812 11

0

5

10

15

20

25

30

35

40

45

50


OCM Units

Resp

on

se T

ime (

Seco

nd

s)

Time to Detect Oil Time to Alarm

31

11

43

14

Target Response Time, 5 secs

Required by MEPC.107(49)

NOTE : For this test oil was injected at 40 PPM oil at the corresponding optimum disperser’s speed for each OCM:The calculated time for the oil to travel from the injection point to the OCM was subtracted from the time measurementsThe blue columns represent the first time that the OCM detected any oilThe total height of the columns represents the total time for the OCM to alarm

December 2009

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List of Contaminants

Test Type Components Description Composition

1.8a Color Dye Formulabs STD Blue Liquid, Lot #3786

1.8b Air Air bubbles Injected with syringe pump for low concentrations and low pressure air with pressure regulator and rotameter

1.8c Solids Iron Oxide (Fe3O4) Particle size distribution: 90% below 10 microns and 10% up to 100 microns

50/50 by weight mixture

SAE fine test dust ISO Fine (0-80 microns)

1.8d Emulsions Allied P-98Mil-D-16791AFFFSimple Green

Emulsifier/detergent mixture

Mixture of equal volumes, prepared using bench-top shaker

1.8e Salt Water “Instant Ocean” Refer to Appendix A for ingredients

Up to 6% of salt in water

December 2009

Test Results/ Findings Contaminant/Interference/Salinity Test – Summary

16

Test Results/ FindingsContaminant/Interference/Salinity Test – Summary


• The Navy in-service OCM was not affected by the presence of interferences/ contaminants at low concentrations. It produces unnecessary recycle at high concentrations of these interferences/contaminants and “fails safe.”

• The COTS unit tested produced critical failures with and without interferences/contaminants when tested under the conditions expected from a failing treatment system.

•The COTS unit tested was not significantly affected by the presence of interferences/contaminants when the sample was conditioned at very high disperser’s speed.

December 2009

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Potential Areas of Standardization for OWS and OCM Systems

• OWS and OCM– Revise ASTM F-2283– Different Type of Oil test – Reliability and maintainability

• OCM– Free oil and droplet size distribution tests – Fail-safe design


December 2009

18

(BACK UP SLIDES)


END

December 2009

19

Test Approach

• Test Set-up is shown in next figure

• Baseline - Navy OCM calibration standard conditions:– Oil type:

• Mixture by vol 50% diesel fuel, 25% 2190 lube oil, 25% 9250 lube oil (used for years as standard in all Navy testing)

– Sample conditioning: • In-line disperser set at 8,000 rpm to produce approximately 20% oil

droplets above 20 um diameter (expected in the effluent of a failing parallel plates OWS)

– Performance results from the in-service OCM unit

• OCMs tested within a range of various operating conditions, oil types and contaminants/ interferences

• Oil concentration was determined by mass balance of oil injected into the water stream


December 2009

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Test Results/ Findings Calibration Test


OCM Unit

0 PPM

Oil Injection (1)

15 PPM

Oil Injection (1)

15 PPM Oil Injection (at higher disperser’s speed)

12,000 RPM 20,000 RPM 23,000 RPM (2)

Navy OCM (ET-35N)

0.16 15.07 - - -

OCM 1 0.78 6.57 15.90 - -

OCM 2 0.01 0.12 - 14.99 -

OCM 3 0.01 0.08 - - 7.91

Notes: (1) Standard disperser’s speed (8k RPM).

(2) maximum disperser’s speed

(3) OEM of COTS units indicated that their units were calibrated to meet the MEPC. 107(49) and that

recalibration will invalidate this certification

December 2009

21

Test Results/ FindingsOil Droplet Size Distribution Test:

OCM Decision at 22 PPM Oil Injection

05

1015

2025

30

0 6000 12000 18000 24000

Disperser's Speed (RPM)

Oil

Co

nce

ntr

atio

n

(PP

M)



Acceptable Region

Critical Failure - >15 PPM Overboard Discharge

December 2009

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Conclusions Summary

• The COTS OCMs tested failed to detect free oil, failed to accurately measure oil under the conditions expected in the effluent of a failing parallel plate OWS, and required highly mechanically dispersed oil for accurate measurements

– These OCMs were not designed to condition the sample – The accuracy of these units will depend on the sample conditioning of the secondary treatment effluent– These units may produce unacceptable overboard discharge if the failure of the treatment systems produces large oil droplets (e.g., cracked membrane, etc.)

• The measurements of the OCMs tested were not significantly affected by variations in pressure or temperatures

•The measurements of all the units tested, including the In-service OCM, are dependent on the type of oil present.


December 2009

23

Conclusions Summary (Cont.)

• The response times of all the MEPC. 107(49) Certified OCMs tested exceeded the maximum of 5 seconds required for this certification (e.g., 11 to 43 seconds)

• The ET-35N was not affected by the presence of interferences/ contaminants at low concentrations. It produces unnecessary recycle at high concentrations of these interferences/contaminants and “fails safe.”

• The COTS unit tested produces critical failures with and without interferences/contaminants when tested under the conditions expected from a failing parallel plate OWS

•The COTS units tested were not significantly affected by the presence of interferences/contaminants when the sample was conditioned at very high disperser speeds.

• OEM of COTS units indicated that their units were calibrated to meet the MEPC.107(49) and that recalibration will invalidate this certification.


December 2009

24

Conclusions Summary (Cont.)

The sampling cell of the COTS units were cleaned between tests to ensure a zero baseline. These units may require self-cleaning capabilities for proper operation.

• COTS units continued operation even with no flow allowing “by-passing” the OCM while the data recorded shows acceptable effluent.

• COTS units do not provide signal output to energize the diverter valve when the OCM is operational and readings below 15 ppm as required for a “fail-safe” installation.


December 2009

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Recommendations Summary

• Performance and reliability shipboard demonstration should be conducted prior to considering these units for shipboard installation.

• Integration requirements should be developed to ensure that the “fail- safe” intent is met if these units are considered by the Navy for shipboard use:

–Diverter valve “Fail-safe” requirements•Diverter valve position to overboard only when received signal from OCM.•Default position of the diverter valve shall be to the OWHT when

–Normal de-energized position–No signal input from the OCM–Actuator failure–Electrical power supply failure

–OCM signal output “Fail-safe” requirements:•OCM shall have consecutives acceptable readings for at least 1 minute prior to send signal to the diverter valve to:

–Verify that the effluent is acceptable prior to being sent overboard.–To avoid constant cycling of the diverter valve that can result in unacceptable overboard discharge and valve failure.–OCM signal shall be immediately interrupted if any reading is unacceptable

• The units tested use some variation of light scattering technology. Other available technologies such as UV fluorescence should be evaluated.


December 2009

Documents

December 20091 Standardization for Oil Water Separator (OWS) and Oil Content Monitor (OCM) Systems In-Service Engineering Agent Perspective December 2009