challenges in the installation and operation of ballast ... · green4sea ballast water masterclass...

Challenges in the Installation and Operation of Ballast Water Treatment Systems

Dr. John Kokarakis

2 GREEN4SEA Ballast Water Masterclass

The process


Questions to reply

► Enough capacity? Limitations

► Enough power?

► Safety? Gas Dangerous Zones

► Hydrogen removal?

► Monitoring-Alarms

► Ventilation?

► Low Salinity-Low Temperature (full flow)

► Training

► Risk assessment/HAZID

► The after peak problem-Harmonization

► Holding time, Dosage, Discharge limits


Installation questions: WHERE, HOW, WHAT

► Find a suitable location (minimize pipe and electrical runs)

► Integrate electrically into vessel system

► Engineer system for Class approval

► Integrate with existing pumps & eductors

► Isometric piping drawings (prefab)

► Usually available only 2D-Data

► Organization & logistics to minimize off-hire


Critical factors to installation

► Classification of the ship

► Type of vessel (tankers: additional safety issues)

► Standards (DIN, DIN EN ISO, JIS, ...) differ in dimensions of joints, pipes etc.

► Small ships have less space in engine rooms

► Operating areas have to remain free (Gangway min. 600x2000 mm)

► Room height has to be considered

► Entrance to existing equipment for operation and maintenance,

► Stairways, emergency exits, man holes have to be kept free


Critical factors to installation

► Operating space for screws, bolts, nuts, handles, ...

► No connections of fluid pipes above electrical devices

► Additional space for insulation

► Systems to be avoided (thermal oil)

► No welding close to / on tanks because of tank coating

► Standard pipe elbows with bending radius of 1xdiameter or 1,5xdiameter (1D, 1.5D)

► Angles of pipes always multiple of 15°

► Minimum distances between pipe bends due to fabrication


Documents for Class Approval

► P&ID of the ballast system including any connections to other

systems (bilge, fire etc.)

► Arrangement of all units and auxiliary systems with critical

importance for the functioning of the treatment system.

► Main Switchboard modification

► Updated electric load tables for all conditions

► Evaluation if new short circuit calculations are necessary.

VFD will not for instance affect the short circuit currents.

► Control system block diagram and power supply arrangement

► List of controlled and monitored points/sensors

► Risk assessment

► Stability calculations .Total weight added must be reported.

► Reinforcements needed due to the added elements.


The limitations

► Treatment process is limited by water temperature and salinity to achieve optimum performance. A heat exchanger might be used to raise the water temperature.

►

►

► Ballast can become contaminated by the

residue/sediment in the tank. This may

necessitate the treatment during de-ballasting.

► Management of dangerous gases is an important parameter to consider when installing BWTS.


Hydraulic constraints

► An orifice might be utilized to limit

flow through the BWT system.

► In case of pump upgrade, assess

the suitability of existing

piping/flanges to the higher

pressure in the system.

► Systems which treat ballast water

during intake only, can utilize

gravity discharge with provision

for neutralization.

►


Installation Pointers

► Installation surveys to ensure that the BWTS is installed in accordance with the approved drawings and BV requirements. On-going surveys ensure correct maintenance and operation and record-keeping on board.

► Makers must provide information on whether system can generate hydrogen or other hazardous gases affecting ballast water tank coatings.

► Plastic pipes are to meet the fire endurance requirements of the BV Rules and Regulations and IMO Resolution A.753(18).

► Transfer of ballast water from non-hazardous to hazardous area may be accepted but not vice versa.

► Ballast from the APT is to be discharged to a hazardous area, piping is to be provided with two non-return valves in series and be at main deck level.

► Penetrations of engine/pump room bulkheads are in general not permitted.

► Spool pieces are removed after ballast transfer and the open pipe flanges be covered by blanking plates adequate for the service pressure.


Problems with filters

► Clogging

► Mechanical failure

► Corrosion

► Water hammer

► Damage due to foreign particles

► Lack of spares-moving parts

► Filters are very heavy !!

► Need robust supports

► Difficult to move

► About 10 m head loss (v2)

► Fresh water washing


Filter impact on BWTS

► We believe that filters are the most challenging part of BWTS and also “sine qua non”. Filters remove/withhold the largest percentage of zoo- and phyto- planktons. 97% and 50% respectively.

► Many of the existing filters have inadequate self-cleaning abilities, resulting in serious clogging problems. If the filter clogs, the ship stops!

► Filter protection – multilayer screens of varying mesh sizes – pre-filtering. Multiscreen solutions.


Filter dimensions - weight


Installation in Oil & Chemical Tankers

► If possible install in a hazardous area (pump room). Such systems must be explosion proof

► Moving parts that can cause static electricity are not installed in hazardous areas.

► Ballast tanks are hazardous areas.

► Systems might be installed in the engine room. Treated water can go to the ballast tanks through the main deck.


How to penetrate BHD separating safe/unsafe


Challenge: Sampling

► Maximize the representativeness of

the water sample (especially for

larger mobile zooplankton).

► Candidate locations in the

discharge of the ballast pump

(where turbulence is very high).

► Isokinetic sample from a pipe

located at the center of the main

ballast pipe is preferable than from

a small pipe attached to the wall of

the pipe.

► Inside diameter of the sampling

pipe should be approximately 10%

of the diameter of the ballast pipe or

1.5-2 times the computed isokinetic

diameter.


Sampling purpose and sampling points

► For BWT standards, samples serve to confirm compliance (qualitative analysis)

► Preferred sampling point for BWT is at discharge of ballast water

► Sampling for BWE standards is usually from the ballast water tanks, taken trough man-ways, air or sounding pipes


Sampling


EPA VGP

► A) BW system functionality monitoring

– BW monitoring equipment calibration (sensors – annually)

– Critical sensors more frequent (pH probes, TRO sensors, turbidity sensors, etc.)

B) Effluent biological organism monitoring

– Biological indicators – bacteria only (heterotrophic bacteria, E.coli, Enterococci)

– 2 times per year (1 time second year), records to be kept 3 years

► C) Effluent limitations for BWTS using Active Substances

– Discharge of biocides or residuals may not exceed instantaneous max limits (e.g. Chlorine 100 mg/l)

– Sampling 3 times in 180 days, then 2 times per year

Calibration Schedule • Electrolyzer Level Switch (1)

• Drain Tank Level Switch (1)

• Pressure Indication & Transmitter for Gas Separator (1)

• Gas Detector (3)

• Seawater Salinity Sensor (2)

• Main Flow Transmitter (3)

• Level Indication & Transmitter for N.A Tank (1)

• TRO Sensor (3)

• Turbidity, color, or suspended solids can introduce positive interference


Ballast water monitoring-Biomarkers

► Indicative analysis: means a compliance test that is a relatively quick indirect or direct measurement of a representative sample of the ballast water volume of interest.

► Detailed analysis: means a compliance test that is likely to be more complex than indicative analysis and is a direct measurement of a representative sample used to determine the viable organism concentration of a ballast water volume of interest.


PSC inspection

► Sampling inspection by PSC

► Position of sampling point(s)

► Alarm on any bypass line

► Ballast Water Management Plan approved by Administration

► Spare parts (e.g. chemical, UV lamp)

► Crew’s familiarization for BWMS operation

► IBWM Certificate

► Ballast Water Record Book

► D-1 Sampling / Salinity

► D-2 Analyses / Indicative

► D-2 Analyses / Detailed