I have wanted to do this in the blog for quite a while; spotlight waterjet experts and their stories in a way that honors them for their unseen contributions, and hopefully is of high interest to those technical minded manufacturing people out there. Well, with Eckhardt Ullrich retiring last month from Flow, I felt I better get to it. Eck is a master waterjetter. He has used waterjets to mine for gold, create anchor holes in icebergs for towing, cut Boeing and Airbus composite wings….
Why not use a more aggressive abrasive than garnet?
A reader asked why we typically use garnet abrasive opposed to the many other abrasives in the world today. After all, an abrasive waterjet can en-train a wide variety of granular material, and yet the vast majority of machines utilize garnet abrasive.
A filter is a filter is a filter…..right? In our next post by Tim Fabian, we discuss how to choose the right filters for your pump. Now, to Tim.
A filter is a filter is a filter…..right? Not so fast. There are so many types of filters available today it is hard to understand what all the differences are. The important thing to remember though, is that not all will work well with your pump. Just like the cleanliness of the water we drink needs to be clean to sustain our good health, a filter that doesn’t stop the bad stuff from getting into your pump is bad for its health too. Even filters that have the same nominal micron value aren’t always created equal.
I’m excited to bring you our first guest post by Tim Fabian. Tim is a renowned waterjet expert, well versed in everything from machine design to daily operation. It is my pleasure to have him as our guest blogger for this week. Without further ado…. Tim Fabian.
A reader asked about Slurryjet, and why there are no ultrahigh-pressure units out there in the world today cutting in production.
First of all, let’s make sure everyone who has not studied the subject understands what we’re talking about here. Abrasive waterjets today are created by pressurizing water, forcing it through a small jewel orifice where the pressure is converted to velocity, and then the abrasive particles are metered into a mixing chamber and accelerated like a bullet out of a rifle down the mixing tube. Abrasive slurry jet is where a water/abrasive slurry is pressurized and pushed through an orifice. It is inherently more efficient because the water and abrasive are going the same speed, and no momentum transfer from the water to the abrasive is taking place.
Having more than one cutting head on an abrasive waterjet should be much more productive than running one head, right?
By understanding waterjet efficiency, and the relationship between pressure and power, you can equip your shop with the most productive system possible. In short, raising the pressure and putting the power through one head is more efficient than running two heads with normal pressure.
In 1984 the abrasive waterjet was released as a commercially available product. It was powerful, it was incredibly versatile; but it took a special operator to run it. Someone who was into it – who had caught the waterjet bug. Why? Because at the time, waterjet wasn’t all that easy to run.
I had the unique opportunity to be such a waterjet operator by getting into abrasive waterjet just one year after it was released. While in undergrad and grad school running the waterjet laboratory and demo center I could reference basic cut speed tables for what was believed (at that time) to be the best operating parameters. The table included water pressure, orifice size, mixing tube size, abrasive size, abrasive flow rate and the maximum cut speed for a dozen common materials at one or two thickness levels.