ship sweat and cargo sweat | cargo handling |
VENTILATION AND CONTROL OF SWEAT
Saturation Point:
It’s the temperature degree when the air saturated by moisture whereas cannot carry any extra moisture.
Dew point:
It’s the temperature degree when the air cannot keep any moisture which contain & start eliminate it by dew or sweat.
Why do cargoes sweat?
What is meaning of Cargo Sweating or Ship Sweating ?
How do you stop cargo sweat?
Type of sweats
Cargo sweat
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Ship’s sweat
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Cargo sweat is the condensation of water vapour directly on to the cargo which done when temperature of cargo less than saturation point of air of holds structure when ship moving from cold to hot area While loading non-hygroscopic cargo..
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is the condensation of water vapour on the ship’s inner structure which done when ship moving from warm area to more cold area While loading hygroscopic cargo.
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AVOIDING:STOP ventilation just recycle the air inside the holds to allow to be the cargo & hull temperatures to be consists.
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AVOIDING: Pumping in a cold air to the holds till SATURATION POINT coming less than air temperature of holds structure.
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CARGO:STEEL & DRAY CARGO
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CARGO :RAICE,COTTON,TOPPACO & GRAIN
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DP is abbreviation for Dew Point
When should you ventilate cargo?
The simple rule concerning ventilation is:
a) VENTILATEif the DB of the air inside the hold is MORE than the DP of the air outside the hold.
b) DO NOT VENTILATE if the DP of the air inside the hold is LESS than the DP of the air outside the hold.
There are six temperatures which are relevant:-
- Outside Air Temperature
- Outside Air Dew Point
- Hold Temperature
- Hold Dew Point
- Sea Temperature
- Temperature of the cargo mass
THE REASONS WHICH EFFECT IN CHANGE OF TEMPERATURE DUE TO VOYAGE:
- Type of cargo.
- Season of the year.
- Weather during (ARRIVAL,DEPARTURE & BERTHING TIME ).
- Ship speed.
- Sea temp.
- Dew point.
