vacuum problem

[paddy737]

Hello. I operate an INTERMAC JET cnc stone cutting machine. Workpieces are held to the machine table with suction cups. The suction cups get their suction from a vacuum pump. My main problem is that ice forms in the plastic hoses that connest to the suction cups, very easily and this causes loss of suction, causing workpieces to move during a machining cycle. I know that the temperature does not need to be low for this to happen as where there is a vacuum water will freeze. I often pour hot water down the hoses to melt any ice and unblock the lines, but this water probably collects in the vacuum tank, cools later and freezes. there is no water drain on the vacuum tank. Im not fully sure how the vacuum pump works but machine is a bout 5 yrs old now and pump is probably on way out.

[ImanCarrot]

Hi, don't know if this will help, but Geof has some neat ideas about vacuum stuff. He stuck a foreline trap in his setup to catch any coolant that got into the system. Blinking good idea!

Here's the link to the thread.

http://www.cnczone.com/forums/showthread.php?t=53796

[paddy737]

Thanks for the help. He uses a domestic water filter and a ball valve as traps. Will look into that but probably will be getting a new vacuum pump soon and i will see if the problem persists.

[67N20]

Hi Paddy737, have you thought about installing a drain valve on the tank. If you are pouring water into the lines to melt the blockage, you prolly have quite a bit of water in the tank.
Patrick

[mosiac71]

We are running 7 Intermac's and even in the middle of winter on night shift I have never seen anything like you describe. I am assuming that the jet runs a similar vacuum setup to the Intermac's I am familiar with. A system with a recycling of water through the tank and a pump "pulling" against this. A few questions...
What sort of reading are you getting on your gauges?
What condition are your seals and hoses on your suction cups?
What is your ambient tempreture when this happens?
Cheers

[paddy737]

Well all the seals on the suction cups are in good condition. The suction guages are reading -70cmHg which is good as its nearly at the end of the scale on the guage. There is a small leak on a seal on the vacuum pump itself and thats what i think is the cause of ice forming in the vacuum lines. Will be getting a new vacuum pump soon but thanks for your help everybody.