Jul 10, 2017 Corporate blog

Diving into an engineering world – a few things about cavitation

Heidi Jäkälä
Heidi Jäkälä
Metso alumni
Having a strong background in business studies and marketing, I had not familiarized myself in the technical field, not to mention valves or anything related. This led me into a situation where I started to question myself, whether I would be able to cope in an environment like Metso, where everyone seems to be an engineer in a field or two.

When visiting the Metso Valve Technology Centre factory for the first time, it felt like jumping into a YouTube video of some kind. I had only seen places like this in books and video clips when studying lean management in the Netherlands during my exchange. Therefore, looking at these lean process lines executing kaizen, automatic trucks moving with the help of motion sensors and cryo-laboratories for testing valve reliability, was truly an experience.

One thing that caught my attention at the factory site was a large demo of a cavitation phenomenon – a thing I knew absolutely nothing about. Last week, I finally got the chance to see the demo in action and meet the Metso experts explaining the reaction that goes on inside the valve.

Cavitation demo video

According to the experts, cavitation is something that happens in liquid applications. It occurs in the opening and closing phase as the liquid is flowing towards a valve in a pipe. At the point when the liquid enters the valve, the velocity (speed) of the liquid flow intensifies to an extreme and simultaneously the pressure of the flow drops under the vapor pressure point. This is when the liquid starts to evaporate and formulate vapor bubbles. As the flow velocity decreases after the valve, the flow pressure recovers and the bubbles start to collapse rapidly. This causes powerful noise and mechanical erosion for the surfaces of the valve and pipes. The noise from cavitation is something that causes one of the biggest health and safety problems for factories, as it is extremely harmful for the employees and the surroundings.

The solution that Metso has brought to the markets is the Neles® Q-Trim noise and cavitation attenuating technology. With this element in the valves, we can decrease the pressure in the pipe and inside the valve in smaller steps, which results to the pressure never going under the vapor pressure point. Thus, we can avoid the erosion and significantly decrease the noise, up to 30 dBA.

The Metso experts, who are the absolute professionals in their field, can explain this complicate-sounding process in a manner that any student, visitor or a customer can grasp an adequate understanding of.  The benefits of using the Neles® Q-Trim are firstly the extended product life cycle, decreased maintenance costs and most importantly, the socially sustainable operations for the wellbeing of individuals and the surrounding communities.

What more did I learn at the factory visit and during the cavitation demo, was that I do not need to be an engineer to learn about a process like that. The only thing I need to be is curious, persistent and friendly towards others, in order to absorb all the new things I have around me. Whether it is getting more information on cavitation, steam cracking process or 3D -printing, it always adds up to my “internal data bank” – the most valuable tool of work.

PS. If you want to read about cavitation in detail click these links to the expert blog, article, Neles® Q-Trim brochure and an expert video about cavitation.