Pump out accumulator on an HP Float system (ammonia)

[benji]

Has anybody have a quick way or idea to pump out the suction accumulator on an HP float system as the receiver is designed to transport liquid and not used for storage?


Any ideas....

[Grizzly]

Then it becomes a large pipe?
Surely you need a liquid seal within it.
Or has what it supplies been disconnected?
Sorry for being so thick.
I can't see what you are trying to achieve?
Grizzly

[RANGER1]

The only quick way is to have a spare liquid reciever or storage vessel to hold the whole charge .
You only have a pilot type reciever so nearly all ammonia charge is in accumulator .

[benji]

Grizzly, i don't think you know what im talking about mate, you totally off track.

[benji]

yes as well as in the evaporator, there is no other liquid receiver thats the problem, i can store it in the condenser cant i?

[benji]

If i haven't mentioned, im changing the sight glasses on the level column on the accumulator.

[RANGER1]

Would have thought that bullseyes could be isolatable , as well as high level switch .
Would give it a thorough look before you do anything like empty accumulator .

[RANGER1]

There's not much chance of holding all the liquid in condensor either if you want to pump it down .

[nh3wizard]

Most of the time the columns have hand valves to isolate them so you can change the sight glass, but if you dont you can put the ammonia anywhere in the system, evap coils, condenser. Is this wet or dry suction?

[Grizzly]

Grizzly, i don't think you know what im talking about mate, you totally off track.


Yes I was wasn't I.
(it was am.)
If you had said you needed to purge the accumulator to work on it.
I would of understood!
Do you have access to an ammonia reclaim unit?
Using it to transfer to the high side.
Don't use them myself.

Just a thought!
(As I don't know the system and don't want to get put down again. )

Could you shut the liquid feed into the unit, running it.
Having dropped the suction control pressure.
This would then back the charge up into the condenser and the system.
At least you should reduce the refrigerant in the accumulator.
Until it cuts out on Low level or LP.
I would assume that it is then a complete isolation of the accumulator.
And purge off the remaining Ammonia (controlled through water of course).

I also use a vacuum pump to eradicate any remaining vapour. Prior to opening up a part of the system.

Hope it helps Grizzly

[Peter_1]

Grizzly, i don't think you know what im talking about mate, you totally off track.

This is because your question is not complete or not complete enough. If you don't give us all the information, then we have to start guessing of course.
I'm almost sure Grizzly has more experience then you have in this field.

[benji]

yes it is a dry suction

[benji]

they installed the system with out bulls eyes, how stupid i try that thanks even if theres not much in the accumulator i can pump the rest out into water, thanks.

[Magoo]

Benji.
Ring me and we will discuss it. I know your system you are talking about. Bring cheque book as well.

magoo

[benji]

Thanks guys, job done apologize for the incorrect explanation. I shut the supply to the accumulator so now the economiser will start filling up and the plant will trip on economiser high level emptying the accumulator.

[Magoo]

Benji.
half right half wrong, the site glass leg has isolation vavs, and a pump-out vav on bottom vav. Why pumpout accumulator?. Old saying "look before starting".
magoo

[Josip]

Hi, benji :)


Has anybody have a quick way or idea to pump out the suction accumulator on an HP float system as the receiver is designed to transport liquid and not used for storage?


Any ideas....

I saw your post where, fortunately, you solved your problem ... but with question like this one above ... we can have a lot of ideas and none will be good for you;)... why ... not enough input info and then we have to guess ....

maybe I sound rude - sorry, I don't want that, but how we can help if we do not know what you need ...


Best regards, Josip :)

[RANGER1]

Benji.
half right half wrong, the site glass leg has isolation vavs, and a pump-out vav on bottom vav. Why pumpout accumulator?. Old saying "look before starting".
magoo
If this is FMC frigopak like in your pictures it does'nt make sense either

[RANGER1]

Thanks guys, job done apologize for the incorrect explanation. I shut the supply to the accumulator so now the economiser will start filling up and the plant will trip on economiser high level emptying the accumulator.
If this is a Frigopak like in your pictures ,it still does'nt make sense , how you filled up economizer and emptied accumulator ?
If thats the case your plant is very short of NH3 and liquid pump would'nt
would shut down on differential .

[Magoo]

Ranger1
It is a Frigopak, and I think we are only getting half the story.
magoo

[RANGER1]

Which half ?

[benji]

It is a frigo pak, the sight glasses are replaced so now i can see the levels in the system. The level of the refrigerant in the accumulator when there is no load is on the bottom sight glass, should it be?

[RANGER1]

If liquid reciever , economizer levels ok then room down to temp turn off fans .
If liquid pump does'nt cavitate then nh3 charge ok .
Possibly giving to much info away , sorry Magoo .

[benji]

thanks will try that

[Magoo]

Benji,
All the points that Ranger1 suggested, and let system stabalize for 15 minutes. You should just see liquid inbottom sightglass. If it is full it is over charged. Double check after 15 minutes and manually load compressor to 100% for a short time, then unload again. You can watch it all on the screen. If pump does not cavitate, you are on the mark.

Ranger1 this is probably too much info..

[benji]

haven't tried that yet, i can only do it when production is not running, never the less on my checks this morning on start-up the micro-controller on the screen said Nh3 pump pressure low and then 15minutes after the pressure just picked up and then it was ok. However it always does this on start-up, suppose it stops cavitating when the liquid is at a lower temperature.

[Magoo]

Benji.
The micro will ignore pump fluctuations during pull down, to avoid nuisance trips etc., The pull down will be slow for first start, as in minimum pulse load rates and reverts to rapid response once machine is 100% loaded.
Last time I was there you had fully opened the oil feed valve to load cylinder, which gives big chunks of slide changes and agrivates the boiling effect in accumulator and pump cavitation. Pull down should take 50 minutes without product in freezer. Any quicker and you create problems for system and yourself,[ HP problems ] mainly the client.I also noted that the HP control point was changed, that can create more problems during normal production. Stop playing with things. This system is not a normal coldstore type application, that has one pull-down in its life, this system pulls down every day in its life, rapid pull down would need a condenser twice the size. Get the picture.
magoo