Emerging Techniques for Clean Bulk Handling in Ports

by B Velan

TECHNIQUES IN TECHNOLOGY

IN TANDEM WITH

TECHNIQUES IN OPERATION

courtesy Vigan Engineering-Unloading Tapioca

DUST DEFINITIONS

Small solid particles, conventionally taken as those particles below 75 μm in diameter, which settle out under their own weight but which may remain suspended for some time.

Dust particles are usually in the size range from about 1 to 100 μm in diameter, and they settle slowlyunder the influence of gravity.

Particle Sizes

• Cement dust 3-100 microns (1/1000mm)• Coal dust 5-1000• Iron dust 4-50• Atmospheric dust 0.001 -40• Grain dust 5-1000• Human hair 70• Flour 1-100Human eye can see 40 micron and higher dust

Operation Dust levels(mg.m-3)

Unloading ship 1-14using bucket elevators Elevator operating 1.5-7(in cabin) On quay adjacent to 69-267 barge being loaded Driving vehicle 13-32in hold of Ship Cleaning holds and 14-23quays Loading lorries Discharging 1-30lorries People in vicinity 1 -6of operations

A dust is considered to be hazardous to health if:

- it has an occupational exposure limit, ie it has been given - an occupational exposure standard or a maximum exposure limit

- it is present at a substantial concentration in air, ie more than 10 mg.m-3 (total inhalable) or 4 mg.m-3 (respirable)

- it is classified as dangerous to health (ie as very toxic,toxic, harmful, corrosive or irritant)

- it is a biological agent, ie it contains bacteria or othermicrobiological organisms

HEALTH HAZARDS OF DUST INHALATION

Allowable dust concentrations for humans PM10 (average 10 micron particles)50 μg/m3 allowable exposure per day over the course of 1 year150 μg/m3 allowable exposure over 24 hours

PORT HANDLING ACTIVITY REVOLVES AROUND DUST PARTICLES OF ABOUT 1-1000 MICRONS SIZE.

MAIN DUST EMISSION POINTS IN PORT BULK HANDLING

• SHIP UNLOADING• SHIP LOADING• TRUCK FILLING

CLEVELAND CASCADES SHIPLOADING CHUTE

PRODUCT LOSS IS AN UNNOTICED (?) ELEMENT IN DUSTY UNLOADING OPERATIONS

DUST ESCAPES WHEN THERE IS

1. LOSS OF CONTAINMENT

2. WIND

containment loss and windage dust generation controlled by modified design of hopper

PRINCIPLE OF DEDUSTING MOBILE HOPPER IN PORTS

DUST CONTAINMENT METHODS IN PORT MOBILE HOPPERS

MEASUREMENT

• Opacity is primary measurement technique for dust emission

• EPA (Environmental Protection Agency USA) 9 is the opacity standard

• Measurement is by trained investigator who compares opacity with standard charts

• Readings are averaged out as per procedure

OPERATIONAL CHAIN• Local Government• Port Authority• Port Managers• Unloading contractor• Crane hire agency• Crane operator• Despatch agency• Equipment owners

• Compliances– Dust levels– Unloading schedules– Operator health and

safety– Operator training– Port regulations– Local Govt regulations– Product integrity

SUMMARY OF RECOMMENDATIONS• Each case is unique-

needs discussion with port authorities and technology/equipment suppliers

• Dust control must be treated on par with loading and unloading operations-as revenue earners

• All concerned-port, union, vendor, operators have to discuss and prepare operation manual

• Ship crane operators should be given pre-unloading briefing

• Equipment suppliers must build in feedback loops for operators

SUMMARY OF RECOMMENDATIONS• Measuring

instrumentation is essential with reports

• Operators must have periodic medical examination

• Separate department must be formed with managerial responsbility

• Clear policy and management

• Standard operating procedures

• Top management commitment

• Quick decision making• Training and awareness• Involve operating

personnel 100%

THANK YOU velan@scorpioengg.comwww.scorpioengg.com