What is scavenge fire Marine insight?
A scavenge fire can occur when the accumulated oil in the scavenge spaces are ignited by blow past from the combustion space. The oil within the scavenge space is present due to the drainage from the piston ring area, and should flow out of the engine under constant “blow down” into a drain tank.
How do you stop a scavenge fire?
Prevention of Scavenge Fire
- Clean scavenge space and drain at regular intervals.
- Keep scavenge space drain open at regular intervals.
- Excess cylinder lubrication must be avoided.
- In case of timed lubrication, the time has to be checked as per PMS.
- Piston rings must be properly maintained and lubricated adequately.
When scavenge fire happens what will be the two immediate objectives?
If a scavenge fire starts two immediate objectives arise- they are to contain the fire within the scavenge space of the engine & to prevent or minimize damage to the engine. The engine must be put to dead slow ahead & the fuel must be taken off the cylinders affected by the fire.
What is a scavenge space?
Scavenge space, as we know, is an enclosed space under the piston of the engine. Stuffing box on down side and piston on top makes it a closed space. And fresh pressurized air is continuously fed into this space.
What is scavenge fire definition?
marine. The fire of flammable mixture (cylinder oil, unburned fuel and carbon) which can collect in the scavenge space of an engine. Fire in the scavenge air space can be extinguished by steam, water mist or CO 2.
What are some problems with fuel injector which will cause scavenge fire?
Though many factors involved are unpredictable, scavenge fires are largely avoidable as they are usually due to maintenance issues like improper setting of fuel timing, choked off exhaust, defective injectors, usage of low-grade fuels, insufficient scavenge air supply, defective piston rings or cylinder liners, or …
What factors does scavenging depend on?
Satisfactory Scavenging Depends on:
- Efficient evacuation of exhaust gases.
- Exhaust ports or valves open before scavenge ports.
- Scavenge ports close after the process of gas exchange.
- Loss of fresh air through exhaust passage to be minimum.
What is the common combustion materials is used for scavenge fire?
The fire of flammable mixture (cylinder oil, unburned fuel and carbon) which can collect in the scavenge space of an engine. Fire in the scavenge air space can be extinguished by steam, water mist or CO 2.
What are the components involved and affected by scavenging fire?
1. Oxygen –this is available plenty in the scavenge space. 2. Heat source- this could happen because of blowing by of gases between piston rings and liner or as a result of any rubbing between two surfaces.
What is scavenge drain?
Scavenging Drain Analysis (SDA) is a major oil analysis to estimate the iron (Fe) content and residual alkali (BN) content in the cylinder drain by analyzing the scavenging drain and system oil. Helps to save the cost by optimizing the cylinder oil feed rate and extending the life of machinery parts.
Why scavenging is required?
Importance of scavenging in IC engine An efficient scavenging is important to ensure sufficient air supply to the combustion. The more effective scavenging system, the better fuel combustion and output.
What are the causes of scavenge fire?
Causes of scavenge fire
- Excessive wear of the liner.
- The piston rings might be worn out or have loose ring grooves.
- Broken piston rings or rings seized in the grooves.
- Dirty scavenge space.
- Poor combustion due to leaking fuel valves or improper timing.
- Insufficient or excess cylinder lubrication.
Who is scavenger fire and safety Pty Ltd?
Scavenger Fire and Safety Pty Ltd includes a Fire and Safety Division, operating throughout the mining, marine and oil/gas industries. Scavenger Fire and Safety has fully trained service technicians employed to service the local area, Intra-State and Interstate when required and have been operating for the past four years in Mandurah.
What is a scavenge space fire?
Scavenge Space Fires can occur in the scavenge trunking of large bore, 2 stroke engines as a result of oil and carbon that has been blown from the cylinders through the scavenge port and collected in the spaces.
What is a scavenge fire Watchkeeper?
It is part of the watch keeping engineers remit to be familiar with the causes, control and prevention of scavenge fires in the main engine. It is also imperative that the scavenge spaces should be cleaned out at every opportunity in port and regular inspection of the scavenge drains to the sludge tank carried out by the watchkeeper.
What are the indications of scavenge fire?
Indication of Scavenge Fire. Engine revolution drops as the power generation in the affected cylinder is reduced. Unstable operation of Turbo charger and may cause surging. Exhaust temperature of the affected cylinder increases, as the cylinder is not receiving fresh air.
