SURVEILLANCE DU CARTER DU MOTEUR DIESEL

La présence de brouillards d'huile excessifs

Une pression de carter trop importante ( blow-by )

Une température excessive des paliers et des articulations mobiles

sont les 3 paramètres favorisant les explosions de carter des moteurs Diesel

IRM propose 3 niveaux de surveillance gradués et complémentaires

Mesure de pression du carter ( IRM )

Donner une alarme si la pression est excessive

Arrêter le moteur au-delà d'une limite dangereuse

Mesure de la densité des brouillards d'huile ( QMI )

Beaucoup plus sûr :

Un point de détection par articulation (mesure faite près du point chaud) La panne d'un détecteur n'a aucune répercussion sur les autres détecteurs Auto-diagnostic permanent et complet de l'appareil Plusieurs niveaux d'alarme Une information et alarme par point de mesure

Système éprouvé, nombreuses références en marine, en remplacement d'appareils concurrents Une étude comparative de EDF-REAM (1989) définit que le QMI est de loin le meilleur appareil de détection de brouillard d'huile pour le moteurs diesel, les compresseurs...

Mesurer très rapidement et sûrement la présence de brouillards d'huile

donner une alarme si la valeur est excessive

Arrêter le moteur au-delà d'une limite dangereuse

Mesure de la température instantanée des organes mobiles ( SENTRY de KONGSBERG )       

Mesurer en instantané la température des organes mobiles

donner une alarme si excessive

Arrêter le moteur au-delà d'une limite dangereuse

MEMO 1 / QMI

17th April 2003

Dear Friends

For your information, we have just come across a website that talks about crankcase explosions.

It turns out this is being edited by an Academic at a Marine College here in the U.K.

If you go to www.google.com  then site ‘oil mist detector' , then look up ‘ recent crankcase explosion ' you will find an interesting article about our product.

Also, it is worthwhile going to an another site www.dieselsafety.org .

Again this lists a number of crankcase explosions.  

This should give you some background information on this subject.


Regards
Brian Smith

MEMO 2 / QMI   –      

The Properties of Oil Mist

It has recently been brought to our attention that not all engine builders and shipyards understand the properties of oil mist.

To correct any misunderstandings we wish advise you as follows:

Oil Mist is only created from three   sources:

Blow-by                                                                                                             / aerosoling

Answer :    This does not apply to crosshead engines

Boiling                                                                                                                  / heat

Answer :   If you have a hotspot e.g. bearing wear

Evaporation of oil splash due to shearing of oil droplets            / heat

Answer :    Evaporation is normal but you must have the right operating conditions to create oil mist.

THESE CONDITIONS ARE:   

The body of the engine must be warm to break down the oil droplets

The lube oil must be hot enough to evaporate.   This can be seen when the engine is running in the engine room.   As the engine starts there will be around 0% reading.   As the engine warms up the oil mist will start to rise and will go on rising until it reaches its normal running level.   The oil mist will then only rise if a condition change takes place in the engine.

We would like to point out that the GUARANTEE for our product is only for replacement of parts and does not cover commissioning on site unless an order is issued at the time of purchasing the instrument.

Commissioning should only be carried out by yourselves, if you have an Engineer trained to do the installation, or by requesting QMI to arrange a commissioning which will incur costs for time, labour, etc.

If you have any questions regarding the above, please do not hesitate in contacting us.

……………………………………….

Brian J. Smith/ 09.01.04