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Anonymous999
28-03-2013, 05:50 PM
For cooling air at standard max uk ambients to -30 degrees C

Air flow required is 60000 litres per minute delivered at -30deg C no less

Cooling of the air is required for 1 hour

Thats all the info i have at present

What options would you gents suggest ?

install monkey
28-03-2013, 09:48 PM
i suggest-get a consultant to spec it:D

frank
28-03-2013, 10:33 PM
With a delta t of 57k I would suggest that you do it in stages as you need high temp, medium temp and low temp systems to achieve the end result

Anonymous999
29-03-2013, 12:27 PM
With a delta t of 57k I would suggest that you do it in stages as you need high temp, medium temp and low temp systems to achieve the end result

Thanks

Nice idea, hadnt thought of that

What sort of kW would i be looking at for this ?

frank
29-03-2013, 09:31 PM
Do you know how to design such systems?

Anonymous999
30-03-2013, 08:13 PM
Do you know how to design such systems?

Im just a little rusty as its been a long time since i did any calcs like this.

Did an Apprenticship in mechanical and electrical, served my mechancial time working and installing Grasso RC611 LPR systems on spiral blast freezers, did some really nice frick screws and also the general run of the mill small recip's like bitzer and prestcold.

Also did some (in their infancy) rotocold rotarys which were also sold by frick in the frick days.

Fitted some of the first danfoss electronic TEV's with the fridge plant running on Toshiba Inverters (again some of the first Inverters in the UK for that).

Used to design systems but we are talking - a long time ago - early rotocold days (anyone care to guess the rough age of those days? )

I moved out of that field and now do a lot of large electrical contracts, renewable energy, solar, control panels, BMS, Inverters (AC and DC), PLC's, Devicenet, Profibus, Can etc all in the range of 22-1000kW.

Have got a very good friend who's a designer with his own consultancy business (HVAC and low temp stuff) but he's on holiday, so i thought i would pop by here and see what ideas the forum could muster up and advice i could get to give me a head start.

So there you go.....

frank
31-03-2013, 07:07 PM
LOL.....quite a lot of detail in such a short life (46 years old??)..

No offence, but we get quite a lot of numpties on here asking similar questions, and when they get the answer, they don't understand it and we don't seem to hear from them again.

Anyway, 60,000 litres/minute equates to 1m3/s, so not a great amount of airflow.

To bring 1m3/sec down from +27C to -30C requires 98.61kW of heat rejection.

You can split this into 3 stages of cooling , high (+27 to +10) 29.41kW, medium (+10 to -10) 34.6kW and low (-10 to -30) 34.6kW and select your equipment to suit.

I would think that you may have issues with defrost though impacting on your -30C requirement for 1 hour.

Anonymous999
31-03-2013, 08:48 PM
LOL.....quite a lot of detail in such a short life (46 years old??)..

No offence, but we get quite a lot of numpties on here asking similar questions, and when they get the answer, they don't understand it and we don't seem to hear from them again.

Anyway, 60,000 litres/minute equates to 1m3/s, so not a great amount of airflow.

To bring 1m3/sec down from +27C to -30C requires 98.61kW of heat rejection.

You can split this into 3 stages of cooling , high (+27 to +10) 29.41kW, medium (+10 to -10) 34.6kW and low (-10 to -30) 34.6kW and select your equipment to suit.

I would think that you may have issues with defrost though impacting on your -30C requirement for 1 hour.

46 - But i started at 15 so a few years behind me

Thanks for the reply

Anonymous999
31-03-2013, 08:55 PM
I see what your saying about 3 stages of cooling.

Are we talking of 3 seperate systems here or 3 evaps ?

I was thinking of a two stage screw set up....

Now as i have been out of play for a lot of years, the makes i sued to have a lt to do with were

Grasso, Frick, J&E Hall and Sabroe

All still in business but albeit changed or new owners etc etc

Any comments on the above manufacturers or any others ?

We did an inverter repair on a 160kW Italian package unt the other day, screw semi - frascold - it has to be one of the cheapest worst piece of engineering i have ever seen, total garbage and it wasnt cheap.....

(Screw blew up after 14 months, the inverter on the second system blew up after 16 months (twin system)) - customer not a happy chappy.....

Anonymous999
05-04-2013, 06:48 PM
Nothing ? No Replies ?

Anonymous999
05-04-2013, 06:50 PM
i suggest-get a consultant to spec it:D

Thats really for another debate / thread

In my opinion there are good consultants and there are bad consultants, in a lot of the industries i work in i have come across a lot of bad ones compared to not so many good ones.

welray
24-07-2013, 07:46 AM
In my opinion get a consultant!!!!!!!!!!!
In a lot of the industries i am work and i have come across a lot of bad ones compared to not so many good ones.

welray
29-07-2013, 06:05 AM
In my opinion get a consultant!!!!!!!!!!!
In a lot of the industries i am work and i have come across a lot of bad ones compared to not so many good ones.
Do you like!!