water cooling

[CNCadmin]

OK I getting all the rest of the stuff I need for my laser, does anyone see a problem with using a 600 gal/hr pump? Is that too much pressure for a sealed co2 laser? Usually I see people using a 500 gal/hr pump.

[JFettig]

Paul, the galons per hour does not relate directly to the pressure, or relate much to the pressure at all. I have a pump thatll put out 350gph with a max of 2psi(wont put out full 350), and another that will put out about 60gph at max of 40psi. so basicly it depends on the pump. What pump is it that your using? what are the components made up of?(aluminum, steel, copper etc.) It is always best to keep the materials in a water system the same so they dont corrode.

I dont knwo what kind of backpressure those components have, so depending on that you could have your choice of many pumps.

Jon

[ynneb]

If in any doubt you can always put a T join in the hose between the pump and the laser. Put a tap on the T so that you can adjust the presure.
But as Jon said, it really depends pressure of the pump and not on the flow rate.
The resistance of the presure in the laser is also a consideration.

[CNCadmin]

Here are the sepcs on the one I bought Eheim 1260 Pump - Centrifugal pump # Pump Output: 635 gph # Delivery Head: 12`1"

[JFettig]

That eheim pump is one of the bigger ones I believe, It should be fine, just make sure to use hose clamps. Im sure the components are made to withstand more pressure than that.

Jon

[Marc Soren]

While I had the covers off of the 40 watt Coherent surgical laser, we read the specs on the coolant pump.(laser units manufactured in Hull, England, with a Japanese coolant pump no less)

The coolant appears to be water with typical ethylene glycol, (antifreeze),

The coolant pump shows 3 numbers for flow, indicating three conditions....(lots of specs for medical equipment)
"MAX FLOW 11/12/11" liters per minute (1 liter ball parks with 1 quart, so 3 gallons per minute, just approximate)and "HEAD 1.5/2.1/1.5 m" , taken to be "m" for meters.

so, different output for the laser and different units, with unknown coolant (until I get documentation)

but at least it is something to compare with for a commercial unit, once you break out the calculator.

[murphy625]

I'd like to break in here to ask a few questions...

What is so special about this water cooler? If your passing water to cool a beam head, wouldnt you be more concerned with input temperature compared to output temperature?
Further, would I be correct in assuming that calculating the required flow rate would be to take the rating of the power supply and design to cool that many KW?
1 Liter of water up 1 deg = 1 BTU.. ??

Am I on the right track here?

Murphy

[trubleshtr]

Pressure is also subject to the size of the pipe area. use the following formula to guess-tamit your set-up. Pressure, flow, and area are all related in designing hydraulic systems.

F
~~~
P | A

Where f= flow (GPM)
p= pressure (PSI)
a= area (SQ")of pipe diameter.

this formula is wrong... I apologize, I've confused it with the formula for FORCE. susbstitue the "F" above as FORCE not flow.

[CNCadmin]

The big problem to me is that 30k is DEADLY and you don't need a hose coming off and allowing water to come in cotact with that voltage. No clamps can't be used because of fitting on glass ends. So to much pressure may allow the hose to slip off. That may not even been a big problem. I'm just plaing ahead, as for cooling the water will flow through a radiator with a fan so I will be able to keep the temps down, HEAT is will kill a laser and less it's life.

[murphy625]

What is the input connection size and the output connection size?

How many KW is the power supply?

Do you know the volume of the cooling area? Square inches? Gallons?

Murphy

[CNCadmin]

Originally Posted by murphy625 What is the input connection size and the output connection size? How many KW is the power supply? Do you know the volume of the cooling area? Square inches? Gallons? Murphy

18-30kv, the tube is 50 watts and 55" long and about 2" dia.

[murphy625]

It doesnt matter how big the tube or the head is..
About 99% of the energy put into a laser is given off as useless heat.. Your not rating your cooling size on the power of the head.. You need to rate it at the power of the power supply that feeds that high voltage to the head.

Also, there is a place where the water enters the cooling jacket.. what size are the in and out ports??

Murphy