Lab Freezer Recommendations
Hello,
Each shift we collect about 40 lbs of samples to bake, analyse, and retain. However, since our shipping freezer is all the way on the other side of the plant we have to place those samples in an upright freezer until the start of the next shift. Only during changeovers do we have enough people to spare to put away the samples as well as collect more and be out on the floor. The biggest problem is that we have new samples every 15 min so our freezer is opening and closing all the time. Adding in that since we run all night and day all week our freezer only becomes mildly chilly and unable to keep frozen things frozen. Often times at the end of the shift when we go to bring the samples to our retention cage we find that they have mushed together or started proofing exploding their wrappings or bags. It used to be ok when we could defrost the freezer every other day but we do not have that ability anymore.
I am thinking that a sub zero chest freezer would be better but I don't know if that will burn out as quick. Each sample we put into the freezer is frozen it just requires we open the door constantly to do our tests. We tried adding ice blocks or other cold things in the freezer but that just made it worse.
Is there a freezer anyone can recomend?
Dear tomato,
Some lack of process info.
Offhand, sampling 20kg every 15 min sounds ridiculous unless it's food for NASA. Is this a US SOP ?
My first suggestion is to change the frequency. :smile: Second suggestion to change the sample size.
Rgds / Charles.C
A slight better alternative would be an upright freezer with drawers/internal doors but a chest freezer is the way to go.
Upright Freezer with Drawers.jpg 6.77KB 2 downloads
Charles re. 20kg a shift. A shift may be typically 8 to 12 hours not 15 mins.
Regards,
Tony
You can get freezers that freeze to -30 degrees
I used to have a bank of them for storing DVI's
Caz x
Charles re. 20kg a shift. A shift may be typically 8 to 12 hours not 15 mins.
Regards,
Tony
Hi Tony,
You're right, missed the "each".
Still stand by the 15 min bit though. Unless it's gold-plated tomatos. :smile:
Charles
Hi Tony,
You're right, missed the "each".
Still stand by the 15 min bit though. Unless it's gold-plated tomatos. :smile:
Charles
Or poor process control/unreliable consistency :oops2:
Or poor process control/unreliable consistency :oops2:
O ye, of little faith !
Charles
We take a 2+ samples for every batch. One to bake and another to retain and possibly more for customer requirements. New bread comes out every 8 min and we have 4 lines combined with 2 lines of cookies coming in every 12-17 minutes. Bread gets baked 5 batches at a time and cookies 2 batches on one sheet.
I will look into sub zero chest freezers. I was just hoping someone knew of a freezer that could handle being opened often or had good recovery time.
Just spitballing:
Maybe try having a second freezer so one can recover while samples are loaded into the other one. Flip flop every hour or other appropriate time scale.
I would guess this would make traceability a little tougher and space might (is probably) at a premium.
We take a 2+ samples for every batch. One to bake and another to retain and possibly more for customer requirements. New bread comes out every 8 min and we have 4 lines combined with 2 lines of cookies coming in every 12-17 minutes. Bread gets baked 5 batches at a time and cookies 2 batches on one sheet.
I will look into sub zero chest freezers. I was just hoping someone knew of a freezer that could handle being opened often or had good recovery time.
I've already posted on freezer types.
Sampling sounds a nightmare, maybe you've looked at these:
can you make bigger batches?
take the relevant samples straight to the other freezer?
move things to make it logistically more practical?
considered your failure rate and if you need to bake each batch?
Regards,
Tony
Our batch sizes are limited by the mixer size so we can't do much about that.
The samples have to be wrapped or rebagged and labled so we can identify them later if there is a complaint. Often times there is no problem and turns out they did not bake the products correctly but we still need to have ours for rebaking in case that happens.
As for moving things we have no place that we are able to move to without disrupting everything else.
We might try the two fridge thing as it won't affect anything so long as both fridges contents are taken down to the retention area at the end of the shift.
I worked in research laboratories for over 40 years. Chest freezers are wonderful if you have to open and close them a lot. The cold just lays in the freezer. If you want an "ultra cold" one, that is lower than the usual, you will find that your samples freeze faster and do not thaw. We used Revco freezers for many years. Revco was purchased by Thermo Scientific, but they are still reliable freezers. They are expensive, and it is best to purchase the 220 (208) volt models because they last longer, but they are a good investment. Consider finding one at auction or refurbished.
Dear Tomato,
It sounds to me like yr main freezing capacity is simply unmatched to yr production output. I know the problem well. :smile:
The capability of using temporary chest freezers will depend on things like total sample quantities involved / their input temperatures / the cooling capacity of chest unit / its design temperature. Basically a problem in heat balances.
Rgds / Charles.C
Lab freezer required very low tempareture working principal and it is very improtant for research samples. we can get this qualities in ultra low freezer to keep sample in it. its working temperature is about -80 to -85 degree celcius.