In part 1 of this diptych “How it’s made; the creation of a drumfilter” (you can read part one of the article here)we were invited by Jan Hogendoorn, the developer and supplier of the drum- and combi-filters Profidrum, to visit the manufacturer of the polypropene housing, where also the drum- and combi-bio-filters of the ECO-series are assembled. In this second part we will visit the inox-processor, where the parts of the drum itself, the housing for the stainless steel-line and, for example, the waste gutter are produced.
The company were we will have our second tour of today is a very large factory for metal and inox processing, so we will need some time to see it all. By the way, the factory is also divided in two buildings: at the locations where the inox is processed the presence of any floating parts of metal dust, the so-called ‘flying steel’, from the metal department is highly unwanted. These particles could come down on the inox and start to oxidate. In addition to the Profidrum drumfilters, the company produces parts for the chemical and food industry. For these applications rust is not done, so the two completely separated building are the solution!
For these applications rust is not done..
One of the employees gives us a tour through all the departments, after we have been informed on the strict safety regulation within the company and we have been provided with wicked safety shoes. We decide to follow the entire production process from the beginning until the end and start with the laser cutter. Here all the parts of the drum are cut into the right size, by a 5kW computer driven laser. This laser burns through the metal plates (up to 10 mm!!) and forms the parts of the waste gutter and the frame of the drum, via a computer program. Very impressive to see how powerful a small light bundle can be and can transform the plates into small parts with ease.
We continue our tour and go to the department setting and machining. Here the cut parts are further processed and set, so that they get their eventual shape of, for example, a small container or a strengthening frame for the inside of the drum. Multiple benches for setting, and of course qualified personnel, make it possible to bend the thickest plates of metal and to set those in all possible shapes.
Very smooth welds prevent accumulation of dirt…
The parts are now in their eventual shape, but still have to be mounted to each other to form the eventual drum. This is done via manual TIG welding with backinggas or by using welding robots, leading to a very high welding quality without any irregularities in the weld. This is especially important for the chemical and food industry, but of course the Profidrum filters also benefit from these applied technologies. Very smooth welds prevent accumulation of dirt and the possible formation of areas where pathogens can then accumulate, possibly causing problems for the pond.
While I amaze myself with the expertise of the welders here in the factory hall, Jan and an employee discuss the design of the waste gutter of the drums. The gutter functions fine, but a minor adaptation to the design could improve the drainage of dirt to the sewer. It becomes clear to me that the products are critically reviewed and that possible improvements are always considered. It is nice to see that there is much discussion between Jan and the manufacturer; good communication leads to improvement of the product.
After the welding the last, but not the least important, action is performed: the staining of the RVS. The drum parts are processed (machining and welding), causing the RVS to temporarily loose its protecting passivated layer. Luckily, because of the property of the material it can recover the protective layer in the presence of chromium. However, when the surface of the material is dirty and the protective layer did not yet recover, the surface can erode. This is unwanted, as the protective layer can only be formed on a clean surface.
By exposing the material to a stain bath containing different acids, possible dirt is removes and the RVS can recover itself in relatively short time. After the bath all parts are ready for assembling the drum. In a large workplace all RVS and polypropene parts are collected and, together with the pomp for flushing, the sensors, the sealing ring, control unit, etc., etc., mounted into a fully automatic pre-filter… Again, a costumer can be made happy with a maintenance-less system for the Koi pond.
Or another application that requires pre-filtering. Namely, Profidrum does not only supply filters for our Koi ponds, but for example also drumfilters in all possible shapes and sizes for zoo’s (the sea aquarium and the coral reef in Burger’s Zoo, in The Netherlands) and for factories where process water needs mechanical filtering.
One sometimes says “Time flies when you have fun”, and that is what I personally experience today. I am a big fan of the Discovery Channel program ‘How it’s made’ and today I had the feeling that I was in the middle of a live show hereof. My hunger for knowledge is satisfied for now and I drive home feeling very content… Jan, thank you for the instructive day!
translation by: Janine Doorduin.