Ammonia Detection Unit

[thejus123]

We are doing plant room for an ammonia, industrial refrigeration plant.

The Client specifications require am ammonia detection unit with a detection of 5000 ppm, to turn off of non-explosion prrof equipments in the room.

I have tried with many suppliers for a detection of 5000 ppm. Any supplier with an off scale detection range of 5000 ppm ?

I enquired Thermal gas, Draeger, MSA, all are having only max detection possible is 1000 ppm of NH3.

Thanks in advance.

[tom_80]

one of this company`s have maybe any solution.

gfg in switzerland and gf (georg fischer GmbH) in germany

sry can`t post the URL

cheers

[Magoo]

Double check with your client, 500ppm sounds more like what is required.

[RANGER1]

Believe Australian standard is 1/5 LEL which is 30 000 ppm .
We suggest only use 1000ppm anyway as it means something is pretty wrong , so shut it down .

[Tycho]

Monicon has some good 4-20mA detectors, but they only go to 1000 ppm



why would they want to go to 5000PPM, that's pretty much a lethal dose of ammonia if anyone walked into the room if it was at 4000 ppm.


on our systems we give a warning and set off the alarm at 250 ppm, then we shut down all ammonia "moving" equipment (pumps compressors etc) at 500 ppm and then we cut all power to the room and start the emergency ventilation at 1000 ppm.


the DNV regulations say that the cut power and start fan limit is 10.000ppm

[coolstuf]

Try Murco,just google them.

[thejus123]

Hi thanks for all the replies.
However i came across with an option in Honey well.
Ammonia detection upto 15000 ppm possible by a manual cross calibration procedure.

[Magoo]

I still would not be around the place at 15000ppm, absolute explosion waiting to happen.

[Tycho]

I still would not be around the place at 15000ppm, absolute explosion waiting to happen.

No danger of explosion unless you are between 150.000 - 250.000 ppm

[Grizzly]

Hi thanks for all the replies.
However i came across with an option in Honey well.
Ammonia detection upto 15000 ppm possible by a manual cross calibration procedure.

OK.
It is time to do some Maths.
2 values are important.
1) PPM ( parts per Million)
2) LEL ( Low Explosion Level ) Exspressed as a Volume percentage, just as Alcohol is!

Typically within the U.K. most Ammonia Alarms give an Alarm warning at 0.75% of LEL.
With total shutdown at 1% of LEL.


And the LEL is 16% = 160,000 PPM (U.K. data applied)

Therefore Alarm warning is 1,200PPM.
and Shutdown is 1,600 PPM.
At 1700 PPM you would get Severe Coughing, cramp, serious irritation to nose, eyes, throat and respiratory system. (30 Min's exposure can lead to death. )

At 5000 PPM you would get Respiratory spasm. rapid asphyxia (Lethal within a few minutes)

Data from the Service Engineers section of the Institute of Refrigeration Engineers.

So please tell us where you are planning to set the alarm at 5,000PPM.
So that anyone with a Brain can avoid working there!!
Grizzly

Sorry just re-read your original post. If the room has just equipment and is never occupied then I suppose 5,000PPM would be acceptable.
But In the U.K. we safe-guard personnel first equipment second?

[brian_chapin]

No danger of explosion unless you are between 150.000 - 250.000 ppm

My guess is that he was thinking this:

If my stationary detector is reading 15,000ppm it's quite possible we've got 150,000ppm at the source of the leak.