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View Full Version : Plate freezers with stand by system



smpsmp45
27-05-2008, 02:54 PM
We have received an offer from a plate freezer manufacturer which states that
" To be able to achieve a better freezing
Only by Having a stand by system - which keeps the plates at Zero Deg during handling time."

What does this mean?

What kind of system is expected to be provided by us?

smpsmp45
30-05-2008, 10:14 AM
I could gather some information on this & it is quite interesting.

mazbut
30-05-2008, 11:13 AM
quite unable to open your pdf files,,,,

anyway, your question is not clear and infact ought to have been explained by the supplier itself.

Wht do you intend to convey by stating ''handling time''? Does it mean time to load-unload the freezer or the time spent in defrosting it after each load?

In the former case , if the freezer has to be loaded the plates should be precooled and if unloaded or defrosted the plates should be allowed to warm up ( by shutting the liquid to it). I do not understand the need for a separate ''stand by system'',,,,perhaps the supplier wants you to opt for a booster system to get lower temp such as -40 C or so.

taz24
30-05-2008, 12:19 PM
I could see the pdf files.
What they are recomending is that you run the plate freezers on standby, keeping them at a constant 0c by the use of control valves and solenoids.

It makes sense to me.
The plate freezers are kept at 0c untill the product is loaded. Yhis they claim keeps the running costs lower because the temp of the plates and other things are kept on standby at 0c waiting for the product.

taz.

mazbut
30-05-2008, 07:51 PM
sounds okay to me but in that case you will have to install a separate compressor to keep the plates cool at the time of loading. The actual compressor or booster installed to cool the plates near the critical temp may be employed but it will add to operational cost especially in places where electricity is expensive. Moreover, do you think operators in third world countries are diligent and honest enough to control by valves and by passes etc run the manually controlled machine room precisely as required, especially during night hours ? ,,,,unfortunately I have seen most operators sleeping or drowsing leaving the whole affair in the hands of the inexperienced helper,,,,thereafter I never allowed a bench in the machine room ,,,just a small stool without back

US Iceman
06-06-2008, 03:14 PM
Keeping the plates cold would help to increase production rates, however the refrigeration capacity will be greatly reduced with no product freezing so the refrigeration system has to have the same capacity turn down. Otherwise the system may short cycle on small dedicated system. On a central system you might not notice the impact.

Tycho
06-06-2008, 07:29 PM
I see a lot of potential service hours on a system like that :D

tedre
06-06-2008, 11:00 PM
I can't see any benefit from this.
Plates are getting cold so quick (only few min.) after open liquid valve. Why wasting time and energy to keep them cold when not in use.

tedre