Need to Spec a 1 LPM Water Chiller for high temp fixed point furnace

Hawaii596 · 08-11-2011 -- 12:39:52

We have a new high temperature fixed point furnace (for 1084.62 Deg C Copper Fixed Point Cell) that I am working on getting installed. I have to get Argon supply set up (I have that figured out), but when using this furnace above 700 Deg C, they recommend use of 1 - 2 LPM (Liters Per Minute) (equals 13 - 27 GPH)chilled water to keep the outer parts cool, and to prolong the life of the heater coils, etc.

We have a surplus chiller I was thinking of using, but it is a high capacity unit (looks like 1 - 5 GPM), and I don't think I can/should use it for this application. Not to mention it is in unknown condition, I have to get an electrician to set up a 20A / 230V circuit, and the big mess needed to get it running (for a unit that probably won't work properly). So.... I am looking at some Aquarium coolers that even those are too high a capacity.

I'm thinking I'll spec out an aquarium chiller that runs on 115V, just big enough for the requirements. Any one have any thoughts or experience in connecting chillers such as this? Or a good vendor to get with. There are so many different ones that it is giving me a headache.

USMC kalibrater · 08-12-2011 -- 06:54:29

Hi,
A few questions:
1) What unit, the furnace or the chiller will dictate the flow rate? i.e Where is the pump
2) If the furnace only needs chilled water above 700 C, how is it calling for the the chiller to turn on or how do you plan to ensure the chiller is running when it needs to be.
3) What is the spec'd cooling water temp and what is the discharge temp (this may be critical especially if you try the aquarium cooler).
4) Are you using a chiller anyhwhere else? If so you may just be able to install a line to this furnace using a flow regulating valve. Your HVAC guy can easily do that.

Hawaii596 · 08-12-2011 -- 12:05:20

The frustrating detail is that the only spec in the OEM manual for this is 1 - 2 LPM for temps above 700 Deg C. I do believe the flow rate has to be set externally from the furnace. There are just an inlet and outlet fitting. There is virtually nothing else spec'd by the manufacturer.

It looks like you could even set up tap water (if you read some of the instructions). There is as mentioned, no spec'd temp values of the water, only to use chilled water at above 700 Deg C furnace settings. I believe this is not at all connected to the calibration accuracy of the system (especially since this is a freeze point cell furnace). It is just to help keep some peripheral parts of the furnace cooled down (in a non-precise way) to lengthen the life span of the system.

We are too small to have an HVAC person. Our entire company has around 500 people, but only 8 people at our site. So I have to do my own research on such things.

We have one chiller (not in use or installed) on site. It is much too big, though and will require a lot of expensive facilitization. It is 220V and will need a breaker set up. It is used, from one of our other sites that closed down (so we don't even know if it works). And mostly, after reading the manual for it, its specified flow rate is 218 GPH (about 16 LPM versus my needed 1 - 2 LPM). So it won't work.

Based on the GPH need, I am thinking of something about like a high volume stand up water fountain. There is an ELKAY unit, floor model that is spec'd at 14 GPH of cold water. I have an email out to the OEM to see if they can recommend a mfr/model that would work. But I need to get this system up and running.

darkness63 · 08-12-2011 -- 15:33:08

Don't know if this will help or not. The old vibration shaker's used chilled water to cool down the housing surrounding the vibe shaker. We still have one in use to this day. We just piped off the sink that was located relatively close to it. A few copper pipes and some valves and some rubber hoses and now when we use it we just turn the valve on to supply water to it and it runs until we shut the valve off. However, I don't know what the flow rate is but I don't think it would be much just water ever is flow out of the faucet. Couldn't be much more than 1-2 lpm. This might be a solution if you are relatively close to a water line located in your facility and just have a plumber come in and hook it up for you. Hope this helps.

USMC kalibrater · 08-12-2011 -- 20:41:58

A water tap might get a little pricey on the water bill if you run the furnace often especially in areas where you get surcharges for excessive consumption.
How often and for how long will it be over 700C
Would this work
make a circulating system with a small circ pump and a length of copper tubing (filled with water), placed in a larger container (50 gallon drum) full of water and circulate it that way. I doubt a furnace requires water below room temp but you may want to check, if so that makes your problem a pricey one

USMC kalibrater · 08-12-2011 -- 20:45:24

to be more specific place a long coil of copper tubing into a big drum of water
basically making your own heat exchanger.
You could slap a cheap rotometer on the side to make sure you are keeping the flow where it needs to be

USMCPMEL · 08-15-2011 -- 14:02:05

I do not think it would take very long for the water to heat up that way? I would think you woulkd have to run it through some type of refrigerant system.

USMCPMEL · 08-16-2011 -- 12:27:21

Maybe find a small refrigerator and poke a few holes in it and run a coil through it to cool the water off? Like side to side I had a friend that heated his inground pool like that except he ran the coil through a wood burning stove...

USMC kalibrater · 08-17-2011 -- 20:38:13

It all depends on what the outlet temperature of cooling water will be from the furnace. Normally its far less than boiling, probably 150 degrees or so. If so at 1 lpm it would take some time raise the temperature in a large drum of water.
It wouldn't be to hard to calculate out to get a fairly decent idea, if all the variables were known. The fridge idea would be good too but you still would need the drum of water, copper line and pump.

USMCPMEL · 08-18-2011 -- 09:16:58

Yes I 100% agree. I was just thinking the fridge could be added to your system not thinking it would be a replacement for your system.

Hawaii596 · 08-18-2011 -- 12:20:23

You guys are putting more thought into this than I have (I mean that in a complimentary way). After my latest round of emails with the OEM, it does look like it can be "tap water."

So, my latest probable solution comes from an RV supply website. I think I am getting a 12 gallon water tank designed to be used in an RV, along with a pump and appropriate tubing. I will fill it with distilled water. It is a copper fixed point furnace which will go up to around 1084.62 Deg C. So it will stay at that elevated temp for maybe a day or two at a time (depending on plateau times). Maybe I could even retrofit some thermoelectric plates onto the outside of the plastic tank, and have them cool it as needed. From emails with the OEM, the chilled water is for the outer parts of the furnace (a metrology lab type furnace); and that is just to keep the outer parts cooled. And according to the OEM person, it is suopposed to prolong the life of the heater coils. You know, we actually have a couple of those little midget fridges that we used to use to store batteries in. They are a little moldy, but I could clean that off. That might be a good idea. If my 12 gallon tank will fit in there... Thanks for that thought.