Help needed for unique project

[Ice Ramps]

Ok,

Here is the project: My friends and I are creating a new extreme sport, our company name is Ice Ramps (iceramps.com). The short of it is we are merging aggressive inline skating and ice skating. We are building a prototype halfpipe that is only 4' high. The ice mat (refrigeration lines) we are using is 16' x 35'. We were told by CALMAC (the company the made our ice mat) that we could find a small liquid chiller around 10 tons that would suit our needs. The problem is that most liquid chillers that are small do not go down the low temps that we need around 12-18 degrees F, with a return temp of say 19-22F. I may be able to lean toward a bit higher temps but not much as we are building this in Alabama and have to allow for ambient temps. I have been told that we may be able to use a freezer unit from a grocery store or related food service items. I am wondering if freezers compressors can be run in series? We have a short video clip of what we have done so far with synthetic ice material on our site but since I have less than 15 post I can't seem to post the link but its on our blog page under the title "Black Friday".

Thanks for any advice you guys can offer,
Dale Campbell
Warrant Officer, US Army

[Brian_UK]

Welcome to the forum Dale, sounds like a 'fun' project.

Hopefully someone here will be along soon with some info for you.

[US Iceman]

The problem is that most liquid chillers that are small do not go down the low temps that we need around 12-18 degrees F, with a return temp of say 19-22F.

That's because the small chillers are almost always built for air conditioning service. It's not a problem of building one for low temperatures for the reasonable tempertaures you mentioned.

I would question the temperatures for the glycol of 12F supply to about 19F return. Most of the glycol chillers I have seen for something like this use an approximate temperature difference of 3-4 degrees.

If there is too much of a temperature difference (TD)between the supply and return temperatures, the ice has some inconsistencies. A small TD helps to hold the ice at a constant temperature.

It's going to be difficult to get a Zamboni machine through the half-pipe though.

[Ice Ramps]

US Iceman,

lol... yeah we get that a lot. We do not plan on having a zamboni on the halfpipe, I have another solution for that problem. What did you have in mind for the smaller units? I have a friend who works in residential HVAC but this is all new ground for him.

Thanks,
Dale

[absrbrtek]

If your sure its 10 tons, buy a 10 ton refrigeration condensing unit and a 10 ton welded plate htex. Add a TXV, some pumps and away you go!! It can be done fairly easily. Try http://www.johnsonthermal.com/ he builds custom equipment. He goes under the handle clydemule in the HVACR forums and seems to be pretty much on top of his game.

[Ice Ramps]

Thanks for the advice there Iceman, another snag is that I have found myself deployed (again) to Iraq. when I return to the states I want to get moving with this project already. I would like to hear more about designing a small unit to do what we need. we are attemting to freeze a 35' x 16' area, and we have a flexible refrigeration line system from CALMAC in that dimension already. Oh, and as far as the Zamboni goes we are thinking of a steam based alternative.

w/r
Dale

That's because the small chillers are almost always built for air conditioning service. It's not a problem of building one for low temperatures for the reasonable tempertaures you mentioned.

I would question the temperatures for the glycol of 12F supply to about 19F return. Most of the glycol chillers I have seen for something like this use an approximate temperature difference of 3-4 degrees.

If there is too much of a temperature difference (TD)between the supply and return temperatures, the ice has some inconsistencies. A small TD helps to hold the ice at a constant temperature.

It's going to be difficult to get a Zamboni machine through the half-pipe though.

[TXiceman]

Check with a company RAE Corporation in Pryor, Oklahoma. http://www.rae-corp.com

They build small custom packages based on some standard chiller concepts. These temps will not be a problem for them.

Ken