Question

During loading of a petroleum tanker, the incoming cargo forces out from the tank its previous atmospheric contents (air-vapour-inert gas)

(a) Explain:

(i) The dangers of venting during the loading via open tank hatches (5)

(ii) Why the pressure / vacuum valve is not used venting (5)

(b) Sketch and describe a patent high velocity vent and state why such device is used. (10)

Answer 1

Part (a)

Fire and Explosion Hazard: Open tank hatches allow the uncontrolled release of flammable hydrocarbon vapors, which can form explosive mixtures with air.
Health Hazards: Crew members can be exposed to harmful and toxic vapors, leading to respiratory problems or other health issues.
Environmental Pollution: Uncontrolled venting releases volatile organic compounds (VOCs) into the atmosphere, contributing to air pollution.
Loss of Cargo: Vapor loss can result in a loss of cargo volume, impacting the quantity of cargo delivered.
Static Electricity: The flow of vapors can generate static electricity, which, in the presence of flammable vapors, can lead to an ignition.

Part (b)

✓ Verified Model Answer (Text Solution)