We ran into a very interesting situation this week that I bet most of you would never have thought could happen. One of our sawguide systems, that has been running for several months, has had ongoing issues with fluctuating water volumes. It got to the point of actually stopping the water to the saws while cutting. We tinkered with valving, system pressures on both the water and the air, and even looked at different types and micron ratings of filters to try and figure this out, with little success.
Backing up a bit, I should explain that this was one of our older designs, from when we were still prototyping and developing the system. In this configuration, we were still running the water and oil out to the guide block in separate lines and mixing the oil and water by simply teeing the two lines together about 4 feet from the guides. This seemed to work very well on most of the systems, but there were a few that had unexplained issues. The customer was also one of only a few that were running a 150 sawguide oil.
On our new designs, we now introduce the oil through a very small orifice that creates a pin-stream of oil into the water. It seems that breaking up the oil into very small globules in the water this way is more successful. The feedback from our customers is that the oil coverage in the new design is more even and less streaking.
But back to this older system, and the issues this customer had. On my last trip through their sawmill, I had an opportunity to stand there for several hours to watch the system and see if I could come up with some explanation as to why it was still fluctuating its water volumes. It dawned on me that one of my other customers had a “PLC” error. In that case, the oil pump was left on and it filled the line up completely with oil. The customer had no water flow after that. Could it be a matter of the thick oil this current customer was using? Was it in large enough globules to plug up the water ports in the guide? Once that happens, the water itself does not have the force behind it to move the thick oil. If the oil wasn’t flowing, the water flow meters were stable, but if the oil pump was turned back on, the water started fluctuating again.
I had one of the new fittings kits shipped out and the customer installed it the next weekend. When I followed up on the install, they said the system had completely stabilized and that their previous water fluctuation problem had vanished.
The long and short of this is that some problems have nothing to do with equipment, but instead are caused by what is run in the equipment. I suggested that they also look at dropping the viscosity of their oil to a 100. With the new mixing components, that will break up the oil into smaller globules, which will be able to pass through the system easier without potentially blocking ports and water flow. Who’d have thought that all their problems came down to the basic science of oil vs water?
Author: Dean Maier
Dean has been in the automated lubrication business for 25 years, with 85% of that time spent in forestry applications. We are delighted to have his insight with this latest blog.
Industrial Autolube International Inc.
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