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Sien
11-12-2009, 02:59 AM
Dear All,

Good morning, i have just designed an air blast freezer with limited space and my air blast freezer uses fans at site.

Pls. kindly find the attached and help me to advise, this design is o.k? or not?

i'm worry for the fans operation at so long time, maybe there are a lot of troubles will occur with the fans such as: broken fan guards, blades and burnt motors....

Hope that can receive yours helps.

Thanks very much indeed.

Yours sincerely,

Sien

mad fridgie
11-12-2009, 10:47 AM
I see a problem, with your fan position, you are likely to get uneven flow through the product.
I would mount the fans at the top left on your drawing.
You need to ensure your that the bottom of the evap is enclosed. (ensuring 100% air flow) Just pick a good quality fan(s)
You want stack velocity of at least 5m/s

Sien
13-12-2009, 09:38 AM
Hi Mad Fridgie,

Thanks very much a bout your advices.

Yes, with this design, i are likely to get uneven flow through the product and of course the bottom of the evap. must be closed for ensuring 100% air flow picking the goods.

In my case, i have no any choices because my customer asked me must be fan at site at this design.

Do you or does anydody have any more ideals, suggestions, advices for this designation?

i'm very worry for operation of the fans in this conditions.

Thanks and good sunday to everybody!

Sweet ice

monkey spanners
13-12-2009, 05:31 PM
I don't design stuff just fix it, but looking at your picture i think if the casing of the evaporator was extended so that it meets the shelving that the fish is on, top and bottom and both sides then all the air has to go through the trays before returning to the evaporator.
It looks like the evaporator is on legs, if this is so i don't think the airflow needs blocking off below it, the less restriction in the air flow the better.

All eveporator fan motors i've know are continuously rated, unless the trays are restricting the airflow and overloading the motors i don't see a problem.

There are two types of fan blade and i forget which is which, one it gets easier for the motor is the flow is restricted and the other it gets more difficult.

Hopfully you won't wait too long for someone who knows more than me to comment :D

mad fridgie
13-12-2009, 09:05 PM
Reverse the airflow,
Add turning vain to bottom of outlet of evap, (Reduce the distance at outlet of evap, Left on drawing)
Increase distance between fan and products. (this will even air flow through product stack)
Re Fans, there are no issues ( as long as you buy quality)

Andy
14-12-2009, 11:13 AM
Dear All,

Good morning, i have just designed an air blast freezer with limited space and my air blast freezer uses fans at site.

Pls. kindly find the attached and help me to advise, this design is o.k? or not?

i'm worry for the fans operation at so long time, maybe there are a lot of troubles will occur with the fans such as: broken fan guards, blades and burnt motors....

Hope that can receive yours helps.

Thanks very much indeed.

Yours sincerely,

Sien

Hello Sein

if you can increase the head height you could use an evaporator such as the searle FM range, or any other top discharge cooler.
Air would enter the right hand vertical space (next to the product), leaving the coil out through the top, turn through 90 degree and along a false ceiling.

http://www.icguk.co.uk/client/chooser/SelectRange.asp?id=31

Kind Regards Andy:)