cooling tunnel

[coolmir]

Hi, could someone tell me about operational conditions and advantages /disadvantages of the cooling tunnel? what would you do to improve this equipement? there is a lot of information about freezing tunnel but, is it the same design as the cooling tunnel? what about its evaporator?
any article you can send me would be appreciated
thanks

[US Iceman]

Here are some links for cooling tunnel manufacturers. There are more to select from. I just grabbed a few to post for your review.

http://www.meincke.com/Bakery%20equi...20tunnels.aspx

http://www.hacos.com/htmlsite/KTHori...ng-Tunnel.html

http://www.nielsen-denmark.com/index...d=21,0,0,1,0,0

Cooling tunnels are essentially the same as freezing tunnels. They cool products such as chocolates, bakery, etc. where freezing is not required, just cooling.

The air can be circulated through the tunnels from ambient air to refrigerated air. The temperatures depend on the product and cooling rate desired.

[Peter_1]

What specific do you want to know?
Improve? If it's proper designed, then it doesn't need to be improved.

Make a proper calculation of the needed capacity.
Make sure you have enough air circulation around the product.

Try to test it first in a smaller basic application. If you need 100 kW to cool it in 90 minutes, then installing 200 kW will not do it in 45 minutes.

Make sure that the air is guided in such a way so that it only can pass through the products.

There may be no gaps between the products, so it allwasy needs to be filled like it was designed.

Sometimes, you need additional fans to increase airflow.

What could be an improvement is installing the motors of the fans outside the room.

Try to recover the heat for other purposes, try to condens as low as possible, try to defrost as less as possible, try to use hotgas defrost if defrost is necessarry,....

USIceman, you mentioned Hacos, I worked in the past on some of their machines. They're located +/- 50 km from my home.

The visit to the fish factory is for tomorrow 02:00 PM , it was postponed because the boss was sick last Friday.

[coolmir]

Thanks for your answers, they were very useful!!!.... I still have a doubt, why do you suggest to condense as low as possible?

[Peter_1]

Condensing as low as possible gives allways the best savings you can make with any refrigeration machine.
This is simply a nature law.

Read once this thread
http://www.refrigeration-engineer.co...ead.php?t=1717

[US Iceman]

I still have a doubt, why do you suggest to condense as low as possible?

If the discharge pressure (condensing pressure) is allowed to decrease, the current draw (amps) of the motor will also decrease. This lowers the pressure ratio (discharge pressure divided by suction pressure all in absolute pressure) and increases the COP.

The compressor capacity will increase slightly also.

The minimum condensing pressure is determined by the overall operation of the system and the ability of the TXV to control superheat and refrigerant flow at the reduced pressure differential.

[Andy]

Thanks for your answers, they were very useful!!!.... I still have a doubt, why do you suggest to condense as low as possible?

Sorry one of the main rules in refrigeration. Low condensing lower power input, higher evaporation, more capacity for the input power

Take a look at a Pressure Enthalpy Diagram and you will see clearly.

Kind Regards. Andy

[Josip]

Hi,

it is very simple ,

just imagine: if you have to deliver a case with beer. (maybe this is not the best example )

What will be easier for you, to deliver it to 5th or to 10th floor

The same is with compressor.

Best regards,

Josip

[jwasir]

Can someone guide me with the calculations for the time required to cool the product inside the tunnels?

[Peter_1]

Only practical tests will give you exact figures.