To OP:
NFPA 15, chapter 7.4: exposure protection
10,2 l.min-1/m² over the surface of the vessel
To others:
Yes, the compound is pyrophoric. It is most probably stored at 10% in hexane to exclude moist.
Yes, you should cool the vessel with water to protect from an external fire. Only if the...
According to several suppliers' websites of gas detectors, a catalytic bead sensor must be installed vertically with the gas sensor pointing towards the ground.
If the gas sensor is not mounted in this way, they say, the gas sensor may not work correctly.
But why is this?
And is a horizontally...
Hi all,
I'm fairly new to the industry. Now my employer wants me to write an essay/article about a subject I am willing to look into. Kind of a small specialization. But I can't find something interesting myself. I'm look into the field of fire risk engineering in chemical, petrochemical...
My initial post holds all data available. From this I can derive three points:
1) t=0s ---> c=43%
2) t=130s ---> c=38%
3) t=600s ---> c=22,2%
So yes I can calculate the leak rate for this case. But as partial pressure and total pressure of the inert gas will be augmented, the leak rate also...
Stookeyfpe,
It's not CO2, it's inert gas.
A) The relief paths/leaks cannot be resolved as mentioned in my initial post.
B) This exactly is my question. How do I do this?
Do you mean that the demanded water pressure at the hydrant is 2 bar?
What kind of hydrant? What is the demanded flow?
What is the pipe size?
What is the pipe material (for estimating the pressure loss due friction)?
First you have to determine the most demanding scenario. For example 2 hydrants working simultaneously. This demands (for example) 2x 1000 lpm at 3 bar. Then your pump according to NFPA has to be:
625 GPM
The working pressure depends on the length, diameter and friction of your pipe. If you...
I've done a fan test for a automatic fire extinguishing system with IG55 following the NFPA 2001, appendix C, enclosure integrity procedure.
Known data
CO2 quantity: 22,8 kg
Real concentration: 43%
Volume room: 29 m³
Max height room: 3,25 m
Minimal concentration: 38%
Temperature in the room...
Hi all,
I don't know how to calculate following problem:
Problem:
I have a room with a certain concentration of CO2. There is a leak which causes the concentration to fall over time.
Known:
CO2 concentration start = 43.0%
CO2 concentration after 10 minutes = 22.2%
CO2 concentration air...
What sort of fire? just A fire
Where has 700C come from? outer wall temperature when subjected to pool fire
why fail at 500? just an estimation
What about outer wall failure? I assume the vessel as lost
What is liquid boiling point? don't know
Is the venting system good enough to handle the...
Yes, the inner tank is filled with liquid. How can i calculate the time then?
Matter of the case is really to calculate when (theoretically) the inner wall will fail, not considering any explosions or leaks.
Furthermore,
I assume a fire under a tank. I assume the tank fails when the inner wall reaches 500°C. That's why I need to calculate the time for this to happen.
I assume the surface as infinite, so no masses or surfaces.
The tank is filled with liquid at atmospheric temperature. How can I...
Well,
For calculating the overall heat transfer coefficient:
1/U = 1/h + D/k
there isn't much air between the walls, and only natural convection occurs. So let's assume
h = 10 W/m²K (which is an overestimation)
D = 0.02 m
k= 20 W/mK (for steel)
1/U = 0.1 + 0.001 = ... so the walls are thin...
Hello,
I'm having difficulties calculating the time to reach a certain temperature caused by radiation. I cannot find any method to get time into my calculations.
Any help?
Specific problem:
Double-walled tank with the outer wall at 700 °C. How long does it take for the inner wall to reach...
