NH3 extra flooded evaporator

[SimonBimon]

Hi

We have 2 tunnels with flooded evaporators running in our plant, and are planning to add one more which will be approx 1,8 times the size of the other two tunnels combined.

Would this necessitate we would have to increase the size of the rest of our plant as well? Can the extra necessary refrigerant be kept inside the new evaporator? We will be running either the 2 prior tunnels, or the new big one, this to streamline the packing and freezing of fish. They will not be run together as we dont have the compressor capacity anyhow.

Can the new tunnel be used as a liquid tank of sorts? I am no engineer, just lookin for a rough answer.

Sjallabais
Simon

[seanf]

Give more details on the system you have at the moment, like is it hot gas defrost, does it have a surge drum, does it have a HP receiver, maybe its a Low Pressure Receiver system.
When the current tunnels are switched off, are they pumped out first before the plant is stopped?

[SimonBimon]

Hi, thanks for responding.

Yes it is hot gas defrost on this system, no surge drum. I have a HP receiver. It is a 2 stage ammonia liquid recirculation system, methinks.

No, the tunnels are not pumped out when stopped.

Included drawing of how the tunnels are connected.20230327_085834-min (1)-compressed.jpg

[seanf]

.................

[RANGER1]

Not relevant

[Harper]

Hi!
When only the 2 prior tunnels or the new fish tunnel is activ at the same time so maby you don´t have to increase the refrigerant charge?

[SimonBimon]

Kind of what i was hoping for Harper. If i emptied the prior tunnels and started the new one after emptying them?

Will have to get a contractor involved anyhow so was just wondering if anyone had any experience with this sort of thing.

[Tycho]

This forum is getting weird... I had like very good post on why SimonBimon may not store excess refrigerant in an evaporator... because as the name says, it's an evaporator and not a storage tank even though it is possible to keep X amount of refrigerant inside the evaporator over time as the temperature rises inside the tunnels or tunnel, the rifrigerant is going to bleed over past the OFV valve, the valve on the right in the drawing Simon made and the refrigerant will migrate to the low pressure tank or high pressure tank of the system, over time...

So if you fill it up and close all the valves, you have created a bomb

If you are indeed in Norway, here are some contractor that I can recommend for this kind of job:
https://industrikulde.no/
https://www.ptg.no/
https://www.oyangen.no/
https://www.mmcfirstprocess.com/

I'd go with MMC, but that's just me

[SimonBimon]

My english is not very good, and i wrote wrong in my first post i see now.
Nevertheless i have my answer now after talking with someone with a bit more knowledge than me.

And no, i was not planning to make a bomb Tycho haha.

Thanks for trying to help anyhow

[Tycho]

My english is not very good, and i wrote wrong in my first post i see now.
Nevertheless i have my answer now after talking with someone with a bit more knowledge than me.

And no, i was not planning to make a bomb Tycho haha.

Thanks for trying to help anyhow

Your English is just fine

I'm in the Ålesund area, If e-mail me I can help out if you want

[Josip]

Hi all,

maybe I miss something ,,, but if there is big enough receiver (there is no any info regarding vessels installed on the plant) and you want to run separately two old evaporators or the new one at time I believe there will be enough ammonia for that kind od operation.

According to your post when you introduce yourself on your plant you have 3,5 t of ammonia, meaning, you must have receiver of at lest 6 m³ i.e. there is probably enough ammonia.

Evaporator/s we can use as ammonia storage only for short time and under control of skilled crew. Liquid ammonia we keep within separators or receiver or transportation truck during repairing on plant otherwise it can be dangerous.


Best regards, Josip