Bulk CO2 System (Fully Controlled System)

Bulk CO2 (Fully Controlled System)

These system are mostly observed in RO-RO vessels.
This is called Fully controlled system because in this system we can control the volume of CO2 to be released.

Working

Bulk CO2 System.

1) When the compartment is identified which has origin of fire and spread of fire by fire and smoke detector.
2) The section valve of that compartment is opened
3) Then Main Discharge Valve of the line is opened for specific period, this specific period depend upon the size of the compartment.
4) When sufficient volume of CO2 has been released, main discharge valve is shut.

About the system :

The Bulk CO2 cylinder has Insulating Layer and Metallic Cladding.
It is independent system, having two independent Compressor, expansion valve and Evaporator, in event of failure of one, other start automatically.
Pressure Switch get its pressure from Bulk CO2 cylinder. Pressure is directly proportional to temperature (Charles Law)
When in ideal condition, when desired pressure is achieved, compressor stop.
Heater is used when ship enter into colder region, where temperature is drastically low, we use heating coil to heat the CO2 to -20C
Isolating valve is use for repairing Pressure Switch
Pressure Transducer sense pressure and trigger high and low level alarm
Level Transducer detect the level within the cylinder
Change over valve is provided before two relief valve, because in case of crystallization of one relief valve other can be operational.
There is High Pressure (H.P) and Low Pressure (L.P), H.P is set to about 27Bar and release CO2 within the CO2 room to extinguish any fire that occurred inside CO2 room, where as L.P is set to 24 to 25Bar.

Topping Up of Bulk CO2 cylinder

1) When in port, ensuring that all the valves are closed.
2) Attach the incoming CO2 connection to CO2 liquid filling manifold.
3) Attach the Vapor recovery line back to the source of CO2.
4) Open Liquid filling line.


Within Bulk CO2 Cylinder
Temperature = -20C
Pressure = 21 Bar

Alarms
1) High Level = When CO2 is 98% volume of cylinder.
2) Low Level = When CO2 reduced 5% of the total content.
3) Opening of Section Valve
4) Leakage of Main Discharge Valve.

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