Onion and potato ammonia cold store

[US Iceman]

HI Josip,

Welcome back. We have not heard from you for some time. I hope all is well.

I looked for some information for you. I have provided several links below for each, onions and potatoes.

Onions
http://www.uga.edu/vegetable/onion.html

http://www.bae.ncsu.edu/programs/ext...3-6/index.html

http://usna.usda.gov/hb66/099onion.pdf

Potatoes
http://vric.ucdavis.edu/veginfo/comm...to_storage.pdf

http://www.uidaho.edu/ag/plantdisease/pstore.htm

http://www.uaf.edu/coop-ext/publicat.../HGA-01024.pdf

http://www.agr.gov.sk.ca/docs/crops/...rageMngmnt.pdf

A lot of reading material, but I think the last one provides the most information.

I hope this is useful to you.

Best Regards,
US Iceman

[Josip]

Thanks US Iceman,

for links and attachments

I have to review all to get as much as possible information about.

In this moment I am in Saudi Arabia, traveling up and down occupied with lot of refrigeration inspection for one mixed Italian -Saudi company. We have to prepare very urgently one offer for one cold store. This is very specific request due to kind of goods to store. Later on if we succeed I will come back with some info about.

I was absent for some time because it is not very easy to come to internet here except for emails. Working all day in the evening I'm tired and still have to finish some reports and so on..

Also they have only a few DSL connections and almost allways I have to use modem with very high speed, sometimes with only 21 kbps,fast ha, ). You must agree with me that is not so attractive to come to RE and read posts. When I come back home I will find a time to review some articles

Here they have a lot of old refrigeration plants (*****s, and ammonia) to revamp but also a lot of new projects.

[US Iceman]

...with very high speed, sometimes with only 21 kbps,fast ha

Morse code was faster than this.

I wondered where you were. Have a safe and prosperous trip.

Good luck with the projects!! Let me know how everything works out.

[Peter_1]

We service a NH3 plant with glycol at -10°C.
Glycol is used to cool cold stores and meat cutting rooms.
What's different compared to onion cold rooms?

We've also done over the years some potatoe cold storages (+/- 5 pieces and biggest was +/- 30 x 15 x 6 m)

What do you need for info because you know better the basics then I.

[Josip]

Hello Peter_1

This will be the same system, primary circuit with ammonia and secondary with glycol for cooling, heating and defrosting.

There will be 4 circuits: cold and hot ammonia and cold and warm glycol

It sounds very simple but when you put all on paper...you are coming to about 2 MW of refrigeration

Due to a long time of onion and potato preservation there are some specific requests like:

- using outside air only if colder than the product temperature, this air could be used for cooling down the product with temperature control for automatic hatches (to save energy a lot of cooling will be only by ventilation, both for onion and potato)

- controlled room atmosphere

- humidity control

- to define complete equipment we have to know as much as possible about complete cooling procedure, then before delivery of goods to market reheating (for example potato to control sugar content) again, an so on...

-SCADA system

- for example potato must be kept above 0C (+4/5) depending on final use and on type of potato, in another hand onion must go down to 0C and for this there must be forced cooling

- we have to keep in mind, those kind of goods are still alive and with wrong procedure it is very easy to loose a lot of goods due to decaying

- let's say it is not a big problem to design cold store for ice cream, but to find out the latest (or just new) news in this field and to design refrigeration equipment I must know what about I have to take care

-links provided by US Iceman were of big help for better understanding how to do that design regarding food preservation process

[US Iceman]

Josip,

I would expect the control of the humidity during the cold weather might be the most difficult. For example, when the hatches or louvers are being opened to the storage space in cold weather.

The low RH of the cold outside air will require humidity injection to reduce product drying. Would you use steam or ultrasonic humidifiers?

Will you use ceiling hung evaporators or large central station air handlers (like large HVAC systems)?

This sounds like a very interesting project.

[Peter_1]

Josip,
Could guess immiediately your question was much more difficult.
Will re-read it tomorrow - it's 02:00 night and coming back from a late dinner with a friend - and look on what points I perhaps can help you.
Which will be very little I think compared to the experience you have.

Peter