leewd
29-06-2012, 10:27 PM
Here's the situation. I work for an egg product company, making hard boiled eggs.
Background:
Cooked eggs cool down in a chilled bath, reaching internal temps of 37-38ºF
Prior to packaging, they are ran through an heated acetic acid (vinegar) bath.
Temps at packaging: Internal at 40ºF and surface temps of 90ºF
We package them using a vacuum packaging line, using heated sealing heads to melt the plastic together. I do not have temperatures of the plastic at the end of the line, I would guess 90ºF
They are sealed and sent down a 15' conveyor, through the wall and 5' into a 37ºF cooler
Problem we are having is after the temperatures equilize we are at 60ºF. Being boxed and then pallitized, it's taking a full week for the product in the center of the pallet to drop below 40F (where we want it). It's reducing our end products shelf life by a week.
I've suggested a chilled bath for after the acetic bath, however money is an issue. I'm wondering if there are any routes we go about on the cheap.
One idea was to try to install a fan and blast the packaging with the cooler air. The thought was the increased air movement with the air from the cooler would speed up heat exchange. Problem is they are only on this conveyor a whopping 6 seconds. Is this even worth considering ? How much quicker is heat transfer with turbulent air flow vs static air?
Thanks
Background:
Cooked eggs cool down in a chilled bath, reaching internal temps of 37-38ºF
Prior to packaging, they are ran through an heated acetic acid (vinegar) bath.
Temps at packaging: Internal at 40ºF and surface temps of 90ºF
We package them using a vacuum packaging line, using heated sealing heads to melt the plastic together. I do not have temperatures of the plastic at the end of the line, I would guess 90ºF
They are sealed and sent down a 15' conveyor, through the wall and 5' into a 37ºF cooler
Problem we are having is after the temperatures equilize we are at 60ºF. Being boxed and then pallitized, it's taking a full week for the product in the center of the pallet to drop below 40F (where we want it). It's reducing our end products shelf life by a week.
I've suggested a chilled bath for after the acetic bath, however money is an issue. I'm wondering if there are any routes we go about on the cheap.
One idea was to try to install a fan and blast the packaging with the cooler air. The thought was the increased air movement with the air from the cooler would speed up heat exchange. Problem is they are only on this conveyor a whopping 6 seconds. Is this even worth considering ? How much quicker is heat transfer with turbulent air flow vs static air?
Thanks