Waterjet - water filtration and cooling.

[Stoney83]

Picked up a used Omax 2652 on the “cheap”. It’s been a bit of a money pit but finally running. It came with an SRS but no SRS hopper. As well as a closed loop system but no chiller. So far we are just running open loop, it’s winter time so the city water is plenty cold, and we only have cut 8-10 hr it’s first week.

I don’t know much about the machines other than I can program them and we have work for one.

The stock plumbing doesn’t quite make since to me.

Its dumping the ADO water into the weir tank. That water is hot enough to make a coffee after it stops cutting. It would seem in summer that water should go straight to the drain to keep the shop cool. In the winter it should go to a heat exchanger to heat the shop but still not to the weir as that water would eventually need cooled if running closed loop.

The other thing that doesn’t make since to me is why Omax designed the SRS system like they did. It seems like another big settling tank. Maybe they work real well? We haven’t actually used ours yet but have 500lb of garnet in the tank already.

A company called Lakos makes centrifugal water filters that look like a perfect fit for waterjets. They come in a variety of sizes and configuration with a couple looking ideal for waterjets. Supposedly they’ll get below a 50 microns particle size on the high end filters and can be fitted with automatic dumps when the get full.

Has anyone used something like this or is the Omax set up the way to go?

 

[Neil76]

Hi there

You right the water coming from the ADO is hot due to the high pressure at the needle end, this would usually be routed directly back to the cutting tank, the close loop system is a different kettle off fish, I would recommend running without this if possible, unless you have water supply issues or your local authority doesn't allow pumping to drain, I say this because the cost of the filters can be high, if you do need to connect this then you will need to run the water through a chiller before if feeds back to the high pressure pump, this ideally needs a supply below 21 degrees Celsius71 degrees Fahrenheit.
Anything above this will compromise the high pressure pump seals.

The Omax SRS is pretty efficient if setup and used correctly, the tank does need a few inches of abrasive in the bottom before it starts pulling anything substantial through, but if you are cutting around 8 hours a day then it can easily pull out 1 tone a week.

Hope this helps you out.
Cheers

 

[Stoney83]

The city water regulations are pretty vague and their water is cold and clean at least this time of year. It basically says if they find something going down the drain they don’t like they’ll let you know and you are responsible for correcting it. I read that as open loop is ok based on the materials being cut. At the same time I want to be responsible with anything going down the drain and don’t like dealing with the city. I would also like to be able to cut anything coming through the door. Aluminum, brass, copper, fiberglass, steel, stainless steel, titanium, plastics, wood ect. and know some of those materials are more problematic than others.

In my mind with very limited waterjet experence what makes the most since is a hybrid system.

Dump the ADO water as it’s just hot city water. Filter anything going down the drain to a real high standard. And if using a close loop system…. pre filter it before it gets to the weir with something that does not require a cartridge filter. Heck you could probably even dump on the “close loop” system after the first or second stage and not need a chiller while dumping really clean water.

 

[Neil76]

Hi there

If you are not cutting anything toxic for example lead then a simple laminar Weir system would work fine for most areas as long as this is maintained correctly.
The dumped water is fine do go straight to drain on an open looped system as this is already filtered down to 0.45microns inside the pump, providing you have the pump filters installed.
In the closed loop system then this would need to be kept within the system to avoid topping up and re filtering city water.

Cheers

 

[rcoope]

Sending the pump water to the tank so you can see where the pipes exit is one way of setting it up that has the advantage of allowing to check at a glance if your dump line and charge pump are sending the right amounts of flow. We had it that way for a long time, like 2007 to 2016, but had a major service at one point and the tech rerouted everything. It's possible that OMAX decided sending it to drain was better. We're a prototype shop so have never cut enough to encounter temperature problems with city water.

 

[Stoney83]

Think you guys are right on all this…and I’m being a bit hard on Omax

Right now we are prototyping stuff and the weir tank is crystal clear in the morning. All the heavy stuff would appear to be dropping out.

Lakos did give me a call and for a Omax 2652…. Centrifugal filters to clear out a basin would likely come in north of 10k but need an expensive pump and other stuff for a ballpark of 25k. Cost would go up for larger machines. That system would likely be profitable for real high volume users of smaller waterjets. For the average guy probably not.

I do think there’s something to be said of centrifugal filters with very low maintenance. Might be a good science experiment.