How to eliminate the Ice frost in a freezer

[gwapa]

After some years in operations ,a freezer has huge amount of ice frost all around.
Some water as vapor form got in side

The freezer is working at -25ºC. It storage ice cream in plastic containers.

The question is How can one get rid the frost out without stop the freezer?
Thanks for your ideas
Regards
Gwapa

[ChillyWilley]

gwapa,

What kind of freezer are you talking about? Is it a upright, chest, walkin?

[boy]

gwapa,

do you mean removing ice build up even though equipment is running?

regards,

[gwapa]

it is a freezer 30 x 60 x 12 m
It has two additional cold room(vestibule). One at the product entry where it is paletaizerred (stack on pallet) .The other one is in the poduct outlet where a group of worker makes the picking and load the trailer
Both vestubule are at -18ºC

Boy ,yes I mean removing ice build up even though equipment is running and prouct are inside
Thanks

[US Iceman]

gwapa,

If you can reduce the moisture infiltration into the freezer, then the frost build-up will sublimate on it's own.

I know that sounds simple to do, but more difficult to provide. If the vestibules are conditioned at -18°C, are the areas adjacent to the vestibules also conditioned at say 4.5°C?

The higher temperatures with evaporators will remove a lot of water in a liquid state by condensation. Then if a part of the remaining water is picked up by the evaporators in the -18°C vestibules (as frost), you have less water available in the freezer to accumulate frost.

One of the other issues with this is... Any moisture flowing into the freezer will form as frost wherever the moisture comes into contact with a surface temperature below the dew point of the moisture. That can be wall, racks, or products. If the moisture is not entrained in the air as it flows to the evaporators, the moisture will stick to the cold surfaces before it enters the coils. I see this a lot of times.

Where the air infiltration comes into the freezer I like to have the evaporator fans blowing at these openings so that the cold air picks up the moisture instead of the walls, racks, or products.

The only other way I know of reducing the moisture is to use something like this: http://www.hcrdoors.com/

Hope that is useful...;)

[gwapa]

Hi US Iceman

Are the areas adjacent to the vestibules also conditioned at say 4.5°C? No the areas adjacent are at ambient conditions . The adjacents area are production rooms and you can find a lot of water on floor due to continuos washing.The temperature is 24-26ºC

I agree with your statemens. however if I could reduce the water vapor entries to the freezer I think the evaporators will take to much time to eliminate the frost . It is due to the fact that the Relative Humidity in the freezer is to high .More than 95%

The HCR courtines reduce the entries of humidity to the Freezer I am not sure if those could eliminate the frost once formed.

[US Iceman]

The HCR courtines reduce the entries of humidity to the Freezer I am not sure if those could eliminate the frost once formed.


They can help to reduce the moisture flowing into the freezer so that the frost already there can sublimate. the air curtain of the HCR door has heat added to increase the moisture holding ability of the air. The cold air of the freezer stays behind this curtain.

I've seen several of these curtains/doors and it is amazing to see and feel the difference. Walking though the door; one step and you are warm and another step and you are cold. They really seem to work...

I believe they have some information on their site somewhere about this.

see this... http://www.hcrdoors.com/hcraction/problem1.htm