*YAWNS*

scarletdp:


And they ask, So After we employ you, is this how you would seek bigger challenges in other reputable larger organizations? Then what will you say.

In contributing my quota to the service of my country, I believe this organisation (NNPC) if not the most, is the largest and I will love to build a carrier here while moving the organisation to becoming the biggest in Africa. (i stand to be corrected by nairalanders)

2 stroke engine has carburator that mix ur air and petrol but 4 stroke engine do not have carburator.
4 stroke, ur turbo charger suck in air and only the air enter through the inlet valve while ur injector and nozzle break down the fuel to a form of gas and they enter from the nozzle.
That is why they call diesel Automotive gas oil (A G O) cos the injector and nossle break it down to gas form and as the nozzle spray it into the compressed air that is already hot, combustion take place

sharks776:


In contributing my quota to the service of my country, I believe this organisation (NNPC) if not the most, is the largest and I will love to build a carrier here while moving the organisation to becoming the biggest in Africa. (i stand to be corrected by nairalanders)

From my own angle, I think is better u mention what attract u to NNPC, such as their core value, carrer growth, their level of technicality etc but not salary, and that those are the things u are looking for in ur carrer life and that u will be happy to develop ur carrer with them

babacha:


Bros in 4 stroke engine, is not the mixture of air and fuel that enter combustion chember, 4 stroke engine
are diesel engine, u don't have any 2 stroke engine that is diesel.
4 stroke engine, air enter first, after the air has been compressed, then the nezzle spray in diesel in form of gas into the combustion chember. That is why u don't have nozzle in 2 stroke engine because the mixture of air and fuel enter the chember from the inlet valve.
But in 4 stroke engine, only air enter the chember from the inlet valve and fuel enter from the nozzle. So they don't mix before they enter
U compress air to make it hot, u don't compress fuel, fuel is fluid and air is gas

Bro, do your research adequately before posting here so as not to mis-educate people. To start with, liquids can be compressed due to the weak inter-molecular forces between them. 2: four-stroke engines could be of diesel or gasoline. The difference is that in a diesel, combustion occurs by just compression of the fuel-air mixture. In a gasoline engine, combustion occurs via spark plugs. This is why diesel engines are said to have a higher thermal efficiency than gasoline engines. The heat generated during compression alone is enough to bring about combustion.

[quote author=babacha post=32705435][/quote]
what an excellent clarification...Thumbs up!

babacha:


The answer is in ur simple harmonic motion, just go back and look at ur simple harmonic motion, especially the velocity of an object in a circular path, then u will understand it more clear why the suction and discharge of a centrifugal pump are usually 90degree but if u still don't understand, we can share it togther here

Bro...I still dont understand bro...I need aw Uare to relate d velocity of a body in a circular path with d angle of an inlet and discharge outlets of centrifugal pump...Thanks Bro!

lobito007:

Bro, do your research adequately before posting here so as not to mis-educate people. To start with, liquids can be compressed due to the weak inter-molecular forces between them. 2: four-stroke engines could be of diesel or gasoline. The difference is that in a diesel, combustion occurs by just compression of the fuel-air mixture. In a gasoline engine, combustion occurs via spark plugs. This is why diesel engines are said to have a higher thermal efficiency than gasoline engines. The heat generated during compression alone is enough to bring about combustion.

Theoretically, liquid are not compressible. In practical, liquid compression is so insignificant. Generally, we compress gas and displace liquid.

KINGTELLER:


I'm a computer Science & Statistics graduate and also Mechanical Engineering graduate

So what do you want to know in Compu Sci.

Everything I used to know and much more...
I graduated 5yrs ago...so I think the basics would be much appreciated...like ...
What as computer science graduate can you contribute to nnpc(pls be explicit...dont need the general common ans)
Again, in which of the subsidiaries would you like to work(I will definitely go for IDSL...how do I convince them...that kind thing)

Thanks as I anticipate your ideas suggestions.

lobito007:

Bro, do your research adequately before posting here so as not to mis-educate people. To start with, liquids can be compressed due to the weak inter-molecular forces between them. 2: four-stroke engines could be of diesel or gasoline. The difference is that in a diesel, combustion occurs by just compression of the fuel-air mixture. In a gasoline engine, combustion occurs via spark plugs. This is why diesel engines are said to have a higher thermal efficiency than gasoline engines. The heat generated during compression alone is enough to bring about combustion.

Go to a mechanic workshop and ask..

There is no 2 stroke engine that use diesel,
Also ask them if air and fuel are mixed before they enter the combustion chember.

This in not theory but practical, u can go and read more

Also the compressibility of liquid is so small that is regarded as incompressible, visit ur fluid mechnics text book again.

I have one question for u, can u tell us which component mix the air and diesel before they enter the combustion chember? I never see diesel engine with carburator
Another question for u, what is the need of compressing the fuel?
Bros go look heavy duty diesel engine very well before u argue. Fuel and diesel meet only at the combustion chember

gbonsquare:

I think its high time U ppl move out with ur distracting factors as the required is now ignited on the thread unless unlike d useless grammatical competition that was holding sway.

You too?

lobito007:

Bro, do your research adequately before posting here so as not to mis-educate people. To start with, liquids can be compressed due to the weak inter-molecular forces between them. 2: four-stroke engines could be of diesel or gasoline. The difference is that in a diesel, combustion occurs by just compression of the fuel-air mixture. In a gasoline engine, combustion occurs via spark plugs. This is why diesel engines are said to have a higher thermal efficiency than gasoline engines. The heat generated during compression alone is enough to bring about combustion.

Let me tell u how the fuel or diesel move in 4 stroke engine

From the tank, the fuel move along the hose to the primary fuel filter, from the primary it move to the secondary fuel filter (if the engine has two fuel filter), from the fuel filter to the injector pump, from injector pump to nozzle, from nozzle to combustion chember,.
If air should enter ur fuel line, ur fuel pump will not work effectivly and ur engine will go off. That is why mechanic bleed the fuel line to remove any air trap.
So fuel and air no dey mix with 4 stroke engine before they enter the chember

babacha:


Let me tell u how the fuel or diesel move in 4 stroke engine

From the tank, the fuel move along the hose to the primary fuel filter, from the primary it move to the secondary fuel filter (if the engine has two fuel filter), from the fuel filter to the injector pump, from injector pump to nozzle, from nozzle to combustion chember,.
If air should enter ur fuel line, ur fuel pump will not work effectivly and ur engine will go off. That is why mechanic bleed the fuel line to remove any air trap.
So fuel and air no dey mix with 4 stroke engine before they enter the chember

You're not seeing your mistake. 4 stroke engines can either be CI (diesel) or SI (gasoline/petrol). It seems what you believe is 4 stroke engines are mainly diesel consuming. Car engine is 4 stroke and some run on diesel, others on petrol.
Get it?

prelinctus:

You too?

Sufficed to say for U to come to nairaland to post anything U muct be extraordinarily careful of crossing Ur "Ts" and dotting Ur "i" simply because of distracting elements like Prelinctus.We need to keep these ppl at bar and move on on this thread.At least sanity is getting returned gradually...

presiade:

You're not seeing your mistake. 4 stroke engines can either be CI (diesel) or SI (gasoline/petrol). It seems what you believe is 4 stroke engines are mainly diesel consuming. Car engine is 4 stroke and some run on diesel, others on petrol.
Get it?

Let me tell u how the air move, from outside to the air filter, from air filter to inlet manifold, from inlet manifold to inlet valve, from inlet vale to chember,

Bros we are all learning, this is practical not theory,
If u tell me the point they mix and the component that mix them, I will agree

gbonsquare:

Sufficed to say for U to come to nairaland to post anything U muct be extraordinarily careful of crossing Ur "Ts" and dotting Ur "i" simply because of distracting elements like Prelinctus.We need to keep these ppl at bar and move on on this thread.At least sanity is getting returned gradually...

I give up. Your case is something else.

presiade:

You're not seeing your mistake. 4 stroke engines can either be CI (diesel) or SI (gasoline/etrol). It seems what you believe is 4 stroke engines are mainly diesel consuming. Car engine is 4 stroke and some run on diesel, others on petrol.
Get it?

Those petro car that u talk about use injector, do u know?

Petro is liquid, u can't compress it

prelinctus:

I give up. Your case is something else.

.
Yes Sir Linguistic Prof!

gbonsquare:

Bro...I still dont understand bro...I need aw Uare to relate d velocity of a body in a circular path with d angle of an inlet and discharge outlets of centrifugal pump...Thanks Bro!

If u use ur hand to spin water that is inside bucket, u will observe that the water will move away from the center of the bucket to the edge creating a vacuum at the center. That is what centrifugal pump does, the empeller spin the fluid and a vacuum is created at the center of the empeller for more fluid to come in. That is why u have ur suction at the center of the empeller.
From simple harmonic motion, the velocity of object in circular part is usually tangential to the circumference, that is why the discharge is always tangential to a particular point on the circumference of the empeller.

Draw a circle, draw a tangential Line to any point on the circumference of the circle, from the point of tangent, draw a line to the center of the circle. Ur 90 degree will appear. The tangential line is the discharge and the center of ur circle is the suction.
Hope is clear?

Interesting thread. No more throwing of tantrums here. You guys are gud I must say. I learn stuffs here mostly late at nyt after work. So painful my job ain't giving me enuf room to prepare. I was part of those u were invited for d interview after d aptitude test for 2011.
It was a friendly interview except for one panelist who refused to smile or nodded his head.

Q - assuming we don't knw abt refinery, Wht can u tell us abt it
Q - what is d process of getting fractions of crude oil called (den I said fractional distillation)
Q - yes we knw its fractional distillation bt Wht is d exact process den I said cracking.
Q - from ur CV I said u took pressure and temperature readings of HP, LP, MP and Export Pump unit. Can u tell us d exact pressure gotten from the Export Pump?

Other questions followed still trying to remember all.


Let's keep Dis room alive wit meaningful comments. I will send email to some of u here at least we can chat offline sometimes. Cheers

Gloom:


Know your P&ID symbols and their uses

Talking abt P & ID please I need a training center for it. Or materials if its possible I learn on my own.

.

where are the Elect/Elect guys This thread is becoming interesting now but I'm afraid it's being Mechanicalized hu!

Pls which of the subsidiaries can Elect/Elect mostly be suited... (OT) precisely

Pls which of the subsidiaries of NNP can welding and fabrication engineering technology fit into?

Pls which of the subsidiaries of NNP can welding and fabrication engineering technology fit into?..

babacha:


Those petro car that u talk about use injector, do u know?

Petro is liquid, u can't compress it

Oga! Get it clear, there are four stroke petrol engines that use carburetor. Look for an old Peugeot 504 engine and you'll see it. We are all here to learn bro..........

I can see you have some good mechanical knowledge, nice one. Here are some questions for your attention

1.) If an engine is not designed to be water cooled (i.e. no radiator) what other means can be used to cool it? Explain the principle behind it.

2.) Why does a two stroke engine generates more smoke than a four stroke engine?

3.) A pump comes alive when powered on but it's not pumping, what could be the problem?

madri4u:
Pls which of the subsidiaries of NNP can welding and fabrication engineering technology fit into?..

bro,u r also a welder? U cud fit into any refinery,NGC,NPDC,NETCO

babacha:


If u use ur hand to spin water that is inside bucket, u will observe that the water will move away from the center of the bucket to the edge creating a vacuum at the center. That is what centrifugal pump does, the empeller spin the fluid and a vacuum is created at the center of the empeller for more fluid to come in. That is why u have ur suction at the center of the empeller.
From simple harmonic motion, the velocity of object in circular part is usually tangential to the circumference, that is why the discharge is always tangential to a particular point on the circumference of the empeller.

Draw a circle, draw a tangential Line to any point on the circumference of the circle, from the point of tangent, draw a line to the center of the circle. Ur 90 degree will appear. The tangential line is the discharge and the center of ur circle is the suction.
Hope is clear?

Babacha..I can confess here that u are too much going by d way u made us understood modis operandi of a centrifugal pump.I was only using idea on d topic concerning centrifugal pump b4 now as I am only experieced in positive displacement pumps and rotor dynamic pump and u know d position of their suction and discharge when compared to just explained centrifugal pumps...thumbs up!

engrjoe:
Interesting thread. No more throwing of tantrums here. You guys are gud I must say. I learn stuffs here mostly late at nyt after work. So painful my job ain't giving me enuf room to prepare. I was part of those u were invited for d interview after d aptitude test for 2011.
It was a friendly interview except for one panelist who refused to smile or nodded his head.

Q - assuming we don't knw abt refinery, Wht can u tell us abt it
Q - what is d process of getting fractions of crude oil called (den I said fractional distillation)
Q - yes we knw its fractional distillation bt Wht is d exact process den I said cracking.
Q - from ur CV I said u took pressure and temperature readings of HP, LP, MP and Export Pump unit. Can u tell us d exact pressure gotten from the Export Pump?

Other questions followed still trying to remember all.


Let's keep Dis room alive wit meaningful comments. I will send email to some of u here at least we can chat offline sometimes. Cheers

Oga u tried but you should have given detailed explaination of fractional distillation and d fractions obtained with d temp at which they distilled off to make it impressive.From d questions u were asked i guess u are a chemical/process Engr...Thanks bro.

Am an elect/elect too, OT category. I tink we r relevant in refinery subsidiary, especially in d area of process control n monitoring.

The Automobile Engrs here wanna scatter my know how with their differing views...Diesel engine with plugs,four stroke engine using only petrol,liquid incompressible...hmmm,and many more.How I with those without much practical idea agree with the real life explainations made by experts.Engr Babacha just dont wanna agree with anyone which is not good esp on this thread.We are all here to learn not to impart...Keep d pendulum swinging b4 those "I'm d best in English" come in!

SomBaby:


Everything I used to know and much more...
I graduated 5yrs ago...so I think the basics would be much appreciated...like ...
What as computer science graduate can you contribute to nnpc(pls be explicit...dont need the general common ans)
Again, in which of the subsidiaries would you like to work(I will definitely go for IDSL...how do I convince them...that kind thing)

Thanks as I anticipate your ideas suggestions.

You will have to table your skills to your working experience, because, IDSL I know are into integrated data management.. SO you have to tailor your response to management of database and networking experience you might have acquired while working.

But Like people said, the interviewers may major their question to your CV content

My 2 cents!!!