Modified Laserscope - DI Cooling loop

[aijii]

I would like to put forward a question to those of you that have successfully split up your laserscope systems...

What do you do with the closed circuit DI cooling water loop ?

Do you permanently leave the water lines connected to the optic table ? Or have quick conncet adapters and just top up the DI water at every show.. etc ?

[Laserman532]

asked and answered

[Laser Ben]

Pat, who makes those high current connectors and what are they called?

[Laserman532]

HV connectors - Supercon from superior electric in bristol connecticut

water connectors - Colder Products Company St. Paul MN

[weartronics]

Hi Adrian,

What do you do with the closed circuit DI cooling water loop ?

I think topping up the water each time is no big deal compared to trying to move the head and the radiator/heat-exchanger/chiller with hoses attached.

Self-sealing connectors are neat, but I found that they measurably restricted the flow rate. Maybe it's not an issue if you have a huge pump and short hoses, but I'm planning to use the existing pumps with 5m hoses between the radiators and the heads. Higher flow rate results in smaller temperature gradient along the rod.

John Guest "Speedfit" system (typically 15mm, sometimes 22mm) seems to be common on a lot of European-made industrial YAGs, so those are the connectors I'm using for Laserscopes now (15mm OD version). I'm using solid-wall flexible tubing inside the chiller and the head and reinforced poly hose between them (with barbed adapters to mate with the JG bulkhead fittings each end).

If you're using a radiator or chiller rather than heat-exchanger Laserscope (i.e. no mains water connection), you might be tempted to use the common Gardena hose connectors, because they're cheap and available at Bunnings. But if you're using a heat-exchanger Laserscope I think it's too easy to confuse the DI loop with the mains water (oops).

I will be documenting my build with some photos in the coming months...

Best regards,

weartronics

[Laserman532]

The connectors I use offer no ill flow characteristics. 1.5 GPM is all you need...flow is generally not the problem it is bubbles and cavitation caused by higher flow rates which is a bigger problem

[weartronics]

The connectors I use offer no ill flow characteristics. 1.5 GPM is all you need...flow is generally not the problem it is bubbles and cavitation caused by higher flow rates which is a bigger problem

I should be clear, the self-sealing connectors I tried look a bit different to yours (I will identify the manufacturer later today), anyway I shouldn't have generalised.

Also, I haven't actually measured the flow rate, I'm measuring the temperature rise across the lamp instead. I put input and output thermistors in the water block underneath the optical table (where the water connections for the detector/filter/shutter system used to go). From what I read, a good flow rate corresponds to about 1 degree Celsius temperature increase per centimeter of lamp, which is what I'm aiming for.

If you buy some of those Chinese digital thermometers on eBay, eg:
http://cgi.ebay.com.au/ws/eBayISAPI....m=350232134170
then the probes fit inside the hose connectors and screw into the water block. It costs about $5.00 AUD for a nice water input/output temperature display on your front panel!

Best regards,

weartronics

[Laserman532]

monitoring the temp differential is a novel idea, however impractical during normal operation. Are you going to vary the flow rate for each current level as detected by the temp differential sensor circuit? I could see where this would be good information if you were designing a laser for the first time to study the system, but the system is proven and it is not a critical measurement during normal operation IMHO.

I look forward to the build photos