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RANGER1
07-05-2013, 09:51 AM
Can anyone suggest maximum level in spare liquid receiver. Will transfer -33 C liquid into empty liquid receiver & will store it there for a period, so will warm up to ambient. When it warms it will expand, how much would be a safe level when adding the cold liquid?

cricri
07-05-2013, 06:18 PM
Hi Ranger,
the volume will increase proportionally to liquid spec weight at -33 / liquid spec weight +??.
I won't tell you more about the safe limit. In the company, a few years ago, a wrong recovering tank was delivered and was not according to the recovering procedure. the tank was overfilled and exploded. a motorway and a rest station had to be closed; many people evacuated to hospital for medical examinations. A bad story, so don't miss your calculation and if possible leave the relief valves fitted.

PaulZ
08-05-2013, 01:55 AM
Hi Ranger
Given it is -33 when you put it in the vessel without doing any calculations I wouldn't fill to more then 1/3 and if possible warm it up as you transfer, as cricri said make sure there are reliefs fitted and vented up high.
Paul

RANGER1
08-05-2013, 10:45 AM
Hi Ranger
Given it is -33 when you put it in the vessel without doing any calculations I wouldn't fill to more then 1/3 and if possible warm it up as you transfer, as cricri said make sure there are reliefs fitted and vented up high.
Paul

Thanks, Its very tempting to fill it more, but as you say it will be probably 80% full when warmed up. Of course I will not fill it anymore due to being then overfull. An easy trap if not aware.

Magoo
09-05-2013, 03:56 AM
Hi Ranger.
the specific volume increase from -35'C < +30'C is 12% for vapour ammonia.

Josip
09-05-2013, 12:40 PM
Hi, RANGER1 :)


Can anyone suggest maximum level in spare liquid receiver. Will transfer -33 C liquid into empty liquid receiver & will store it there for a period, so will warm up to ambient. When it warms it will expand, how much would be a safe level when adding the cold liquid?


Not sure, if you can do it, but maybe is better to empty system from HP receiver (transfer gas ammonia with compressor from -33 C separator to inter-cooler -10 C (if) then from inter-cooler separator to condenser and then empty from HP receiver) will take some time, but spare receiver you will fill with warm (environment temperature or little sub-cooled, if) liquid ammonia and then you can go up to 75-80% of the level within spare receiver ... there must be safety valve

This is my suggestion (I did it on that way) ... no need to take care about liquid expansion and pressure increase when -33 C liquid come to environment temperature ... provide a high pressure hose for ammonia and connect one end to gas connection on the spare receiver and another end back to gas connection on separator -33 C or to gas connection on the inter-cooler -10 C ... with HP within receiver transfer will be very fast ...

at -33 C liquid transfer there is a problem with flexible hoses too .... so I prefer to transfer warm ammonia ... 30 C/12 bar

HP-high pressure

No need to say ... be careful .... very careful .... check every connection more times ... before transfer you can check all transfer lines (liquid and gas) with high pressure gas ammonia from HP receiver for safety and for possible leaks ....

This kind of work is very sensible and no need too many people around ... just need to be patient ;)


Good luck...

Best regards, Josip :)

RANGER1
09-05-2013, 09:45 PM
Hi, RANGER1 :)




Not sure, if you can do it, but maybe is better to empty system from HP receiver (transfer gas ammonia with compressor from -33 C separator to inter-cooler -10 C (if) then from inter-cooler separator to condenser and then empty from HP receiver) will take some time, but spare receiver you will fill with warm (environment temperature or little sub-cooled, if) liquid ammonia and then you can go up to 75-80% of the level within spare receiver ... there must be safety valve

This is my suggestion (I did it on that way) ... no need to take care about liquid expansion and pressure increase when -33 C liquid come to environment temperature ... provide a high pressure hose for ammonia and connect one end to gas connection on the spare receiver and another end back to gas connection on separator -33 C or to gas connection on the inter-cooler -10 C ... with HP within receiver transfer will be very fast ...

at -33 C liquid transfer there is a problem with flexible hoses too .... so I prefer to transfer warm ammonia ... 30 C/12 bar

HP-high pressure

No need to say ... be careful .... very careful .... check every connection more times ... before transfer you can check all transfer lines (liquid and gas) with high pressure gas ammonia from HP receiver for safety and for possible leaks ....

This kind of work is very sensible and no need too many people around ... just need to be patient ;)


Good luck...

Best regards, Josip :)
Thanks josip & everyone, unfortunately I had to remove approx 20 tonne of ammonia into empty cylinders in vacuum. Plant is being partially decommissioned within a time line, so cannot spend to much time doing it. The accumulator has plate freezers with no product, or load. I will used its liquid pump to transfer directly into empty cylinders, which each hold 2 tonne & can only be filled to 80% full, at ambient temperature. I had 2 days to do it, all ok filled cylinders to approx 50%. Will monitor levels as they are an ice block.

Magoo
09-05-2013, 11:51 PM
Defrost plates and get liquid above 0.0 C and only fill bottles to 30 % by weight.The volume will double at +20 C.

mad fridgie
10-05-2013, 03:34 AM
You get a 15% (give or take) increase from -30 to +30c Liquid NH3 and about 25% for upto 60C, so to be safe, fill your bottle at -33C to no more than 70%

Josip
12-05-2013, 11:38 PM
Hi, RANGER1 :)


Thanks josip & everyone, unfortunately I had to remove approx 20 tonne of ammonia into empty cylinders in vacuum. Plant is being partially decommissioned within a time line, so cannot spend to much time doing it. The accumulator has plate freezers with no product, or load. I will used its liquid pump to transfer directly into empty cylinders, which each hold 2 tonne & can only be filled to 80% full, at ambient temperature. I had 2 days to do it, all ok filled cylinders to approx 50%. Will monitor levels as they are an ice block.


Time is quite short and job is big and very dangerous ... maybe you can drain ammonia into 2 or 3 cylinders in the same time (depending how many ammonia pumps you have available).

Anyhow, good luck and take care ....

Read my SIG, please ... last bottom row

Best regards, Josip :)

RANGER1
13-05-2013, 10:19 AM
Hi, RANGER1 :)




Time is quite short and job is big and very dangerous ... maybe you can drain ammonia into 2 or 3 cylinders in the same time (depending how many ammonia pumps you have available).

Anyhow, good luck and take care ....

Read my SIG, please ... last bottom row

Best regards, Josip :)

josip, Ammonia cylinders have 2 25mm entry ports so no problem hooking up 2 hoses at once, thanks for advice.