Refrigeration System with Ammonia

[gwapa]

TXiceman / US Iceman Thanks for your tips

The anti-siphon hole in the top of the inlet elbow inside the vessel is very import
Thanks again

[US Iceman]

These are the items and tips you do not find in books. Similar to using vortex breakers in other vessels.

[The MG Pony]

These are the items and tips you do not find in books. Similar to using vortex breakers in other vessels.

I grew up in a loging camp next to a hydrodam and a fish hatchery, and seeing how the water would form vortexes at every chance/ fast forward to now/ I all ways wondered how they dealt with any vortexes that would form in the ***** systems! Especialy the larger receivers!? Neat how they do it with the NH3.

[TXiceman]

I use the same type vortex breaker in ammonia or "*****" systems. But you do need a vortex breaker at every liquid outlet of a vessel, whether it is to a pump of let down to another vessel.

Ken

[Rinaldo1Z]

Hello Samarjit Sen

I would recommendate a two-stage-system with CO2 as lowstage refrigerant and ammonia in the high stage circle. You can design a DX system if have some coldstorage application and a flooded system for freezing tunnels. If you built a flooded system with CO2 watch out for the oil return concept, because compressoroil is in general terms miscible with CO2.

Best regards
Rinaldo1Z from Switzerland

[US Iceman]

Welcome to the RE forums Rinaldo1Z. Can you tell us what type of work you do in Switzerland? You can post your reply in the Introduction area of the site.

Look forward to seeing future contributions from you.

[Samarjit Sen]

Hi Rinaldo1Z,

Sorry for the delay in replying. We do not have many plants of CO2 in our country, but there is a project where Ice Cream is to be hardened and subsequently stored. The hardening tunnel will be at -40oC and the Storage at -30oC. I would like to use CO2/NH3 for this application.

Can anyone provide me with a schemetic diagram for the this system. It is like any other cascade system, but what I would like to know are the safety features and the equipments to be incorporated.

[S.K.VARDE]

Dear Mr.Sen

You are intending to harden the ice cream. The recomended temperature for the same is -40 deg.C and even below. -25 to -18 is the preservation temperature of the hardened ice cream.

Size of the each batch and the production of the ice cream per day will decide the type and the size of the refrigeration system to be employed.

you should specify the same.

[Samarjit Sen]

Dear Mr. Varde,

Ice Cream starts hardening from -18oC core temperature. Generally the Hardening Rooms or the Hardening Rooms are maintained at -40oC. At this temperature usually the hardening is completed within 6 hrs time if not earlier. We have installed some Hardening Rooms with R 22 system and had no problem.

I am now interested in using CO2 as the refrigerant for the hardening chambers. I am seeking information on this and other than the forum, I have collected informations from other sources.

[Ramesh J Mysore]

What I had referred was semi hermetic SCREW compressors.

No I am not going to make any component myself. I would like to procure these from the regular manufacturers.

Please let me know using screw compressors would be suitable and are they suitable for such applications. I am completely depending on you all to help me out, as I have always done good jobs and am known for the same. Till now I have worked on all refrigerant other than ammonia, and as such would like that in case I take it up, it has to be done in the best way.

Dear Samarjit,

You can go for open type screw compressor of single stage machine or two stage reciprocating compressor with flooded type evaporator. You can source evaporator & compressors from OEMs .other shell & tube condenser and receiver can be source localy but manufacturing standard should be compile with ASME CODES.

THANKS

Ramesh Mysore

[Samarjit Sen]

Hi Ramesh Mysore,

It is nice to have you here. I am trying out the various application and learning the system with Ammonia. As you know in our country, Ammonia System mis still pretty old, due to which there are frequest failures. In this forum you will find members who are vary learned and helpful.

I have also noted your suggestion. Please PM to me your contact number.

[Samarjit Sen]

Hello Mike,

It is a old thread and more to my present requirement. At present we propose to use a single two stage ammonia compressor with two evaporators. The defrost system we propose to use is electrical. The Evaporators are from Kuba, Germany. These Evaporators have bottom feed.
In the drawing attached in this thread, you shown a drawing with top feed. Should there be any change.
Need your assistance for making the layout.

Thanks in advance

[PVA]

Will you please advice me as to who are manufacturing two stage ammonia recip. compressors. Generally what I have seen in our country, they use two seprate compressors one for the high stage and the other as the booster.
Since I am new in ammonia I shall follow the advises from you all of the forum.

Dear Samarjit Sen,

GEA Grasso makes two stage ammonia recip. compressors. And this compressors
has well proved to be in our country.

Grasso's recip. compressors are fully welded, the main advantage of this type of construction is the absence of water cooling on the compressor resulting in lower investment and running costs. The externally positioned “air cooled” cylinders make use of natural heat dissipation by means of convection & radiation. At present, when the price for water is expensive enough, this condition is one of main in a choice of the compressor.

[nike123]

Dear Samarjit Sen,

GEA Grasso makes two stage ammonia recip. compressors. And this compressors
has well proved to be in our country.

Grasso's recip. compressors are fully welded, the main advantage of this type of construction is the absence of water cooling on the compressor resulting in lower investment and running costs. The externally positioned “air cooled” cylinders make use of natural heat dissipation by means of convection & radiation. At present, when the price for water is expensive enough, this condition is one of main in a choice of the compressor.

Sorry to inform you, that dear Samarjit is no longer with us on this world!

[icecube51]

i am new at this forum, and has followd this topic.

i have a great interest in NH³ , and want to now how this story has ended.
wat kind of compressor was aventualy used, is there a drowing we can see, or the explaned setup for this particular plant.

wat is eventualy the outcome??

[PVA]

Sorry to inform you, that dear Samarjit is no longer with us on this world!

Oh... it's not good,
thank you for information.

[Miroky]

I would like to ask if You have any catalogues with technical data for freezing tunnels and if yes, can You provide these catalogues for me. If not, can You please tell me or give me directions where I can find the information I need.
Thank You in advance
.
Regards,
eng. Miroslava Rasheva

[nafiz]

Hi all, pls can anybody explain to me what is the pump rate for example 5:1, 4:1
Thanks

[Segei]

Hi all, pls can anybody explain to me what is the pump rate for example 5:1, 4:1
Thanks

5:1 Pump supplies 5 units of liquid ammonia to the evaporator. 1 unit evaporates, 4 units go back to the receiver.

[Gaafar]

Thank you Iceman. The total refrigeration capacity shall be about 30 TR. There shall be in all 6 nos. of evaporators. 3 shall be maintaining a temperature of -40 Deg. C and 3 will be for -30 Deg. C inside the room. What would you recommend.

30 TR not worth to go to ammonia and flooded system you can use dx system, however if you read frick bulletins from york can giveyou a good guidelines for the custom engineered systems, you have to select compressor, then condnser (heat of condenser equal compressor power plus refrigeration inyour case 30 TR =100 kw,
you have to select receiver, surge or recirculated vessel (equivalent to throttling)
as a rule of thump (two third of reciver volume =condenser volume + evaporator volume and 10% for tubes)

[charlie n]

[QUOTE=Gaafar;168749]30 TR not worth to go to ammonia and flooded system you can use dx system,

It's often more economical over the life of a system to use ammonia even for 100 kW. Over the years, I've built several 75 kW flooded ammonia systems economically. In fact I built 3 or 4 systems of about that size in Saudi back ion the late 90's.

[PVA]

I would like to ask if You have any catalogues with technical data for freezing tunnels and if yes, can You provide these catalogues for me. If not, can You please tell me or give me directions where I can find the information I need.
Thank You in advance
.
Regards,
eng. Miroslava Rasheva

Dear Miroslava Rasheva,
If you need freezing tunnels you can look next companies:
Aerofreeze Systems
http://www.aerofreeze.com/en-ca/Pages/default.aspx,

Eurotek Engeneering
http://www.eurotek-eng.co.uk/

Intec
http://www.intecvrt.com/