Metso Insights Blog Mining and metals blog Redesigning the furnace nozzle
Mining Metals refining
May 31, 2019

Redesigning the furnace nozzle

The primary air nozzle, also known as the furnace or FBF nozzle, is one of the key proprietary design items in the alumina calcination technology offered by Outotec. The furnace nozzle has gone through many design optimizations in the past 30 years to stay up with the latest plant engineering design, as well as material science. The process of standardization of FBF nozzles was initiated in 2009 and a new design, the EasyNozzle, was introduced in 2011. Since then, it had been installed in five calciners, delivered by Outotec as greenfield projects in the recent years.
furnace nozzle

The manufacturing of the nozzle cap had been complicated and costly. As a result, after proving the design superiority, Outotec was confronted with the request from operators to develop a competitive product. In 2018, a new manufacturing method of the EasyNozzle was tested, with reduced cost by 60% and easy availability on the supply market worldwide. The EasyNozzle is available in two standard sizes and can be installed in all calciners, delivered by Outotec over the last 3 decades.

We asked Steven Yu, our alumina services product manager, to tell us more about the latest EasyNozzle design and nuances of the R&D work.

Steven, please tell us about yourself. Do you enjoy working in the R&D field?

Having completed my engineering degrees (major in computational fluid dynamics) in China and in the USA, my first job with General Electric as mechanical engineer for locomotive component design equipped me quickly with practical manufacturing know-how and material science (metallurgical knowledge). After an enjoyable interim-journey in the maritime / shipbuilding (LNG ships) sector, I joined Outotec in 2011, stepping into the mining and metals industry, which is as international as maritime. I enjoy working in the field that allows me to get to know different cultures, to learn and make friends with people from diversified backgrounds, in addition to my passion for technologies that Outotec offers.

How did the need to create a new design of the furnace nozzle appear?

As Isaac Newton used to say, his achievement was "by standing upon the shoulders of giants", and so was our work on EasyNozzle. The primary air fluidizing nozzle for the Outotec alumina calcination has gone through generations of design changes, with efforts from mechanical and process engineering colleagues who had applied trial and errors and their sound engineering judgement in more than 50 calciner projects we had delivered. About 10 years ago, the concept of the EasyNozzle came into being. However, the product lacked application data to justify the price tag (3-4 times more than the older design). And when a product does not sell itself on the market, then it is a "dead" product that either must be redesigned or improved.

How many people were involved in developing the EasyNozzle?

It is a product of teamwork. We have colleagues from divisions in services, engineering, procurement, and supply quality. The Outotec R&D facility in Frankfurt helped to test the pilot Nozzles.

What were the main factors in defining our latest EasyNozzle design?

We name our latest EasyNozzle design as EasyNozzle FFM version, where FFM stands for its birth place – Frankfurt am Main (the metropolitan city near the Outotec Oberursel office), and more critically it stands for "Fit for Market".  Thus, the main factors were marketability (price/function relationship), design and manufacturing soundness (that the newly chosen design and manufacturing method does not undercut these), and lifetime.

What is the lifetime of the EasyNozzle?

Compared to the previous designs created earlier than 2010s, the EasyNozzle's lifetime, as statistically proven, is 3 to 5 times longer than the lifetime of earlier generations of primary air fluidizing nozzles.

What materials are used to manufacture the EasyNozzle?

This is our know-how in the 40 years of calciner design. We have tried more than 15 heat resistant stainless-steel grades and combinations! With the new design, we have 2 versions of materials – one for the normal temperature of modern Outotec alumina calciner design, and one for the slightly elevated temperature (e.g. for older plants with wider temperature fluctuation).

How the idea of creating the new cost-effective manufacturing method, presented in 2018, was born? Was it easy to implement?

The initial idea started in quite many brainstorming sessions with Mr. Eugen Weissenburger and Ms. Elena Werchowski, Outotec’s product line experts. To bring it to life, it took us less than a year, but a lot of efforts with the above-mentioned team of 20 to 30 Outotec professionals in different functions. There were bumpy moments, but Outotec’s vast expertise in plant & mechanical engineering, material metallurgy and supply chain management enabled successful launch of the product.

What makes Outotec’s EasyNozzle different from competitive alternatives?

Quite many plant operators still purchase replacement nozzles from local "neighbor" workshops that fabricate the nozzles with original drawings from Lurgi. These nozzles are not optimized in terms of design and functionality. More importantly, the buyers must live with the fact that they have to completely change out the nozzles in 1-2 years.

What benefits does Easy Nozzle provide?

As the labor costs increases and operating and maintenance practice at customer sites gets more complicated, it is wiser for customers to consider the Outotec EasyNozzle. It offers a monobloc cap body which does not fail prematurely compared to the older design that has at least one welding seam on the caps which frequently fails. With fallen caps, the alumina bypass (backflow) into the primary air manifold intensifies the wear of the nozzles even faster. With the in-house CFD and thermal simulation, the EasyNozzle has been adopted with better features in fluid dynamics and has proven to reduce key alumina product characteristics such as particle breakage. The EasyNozzle plus Outotec's latest EasyBox (Windbox to replace bullhorn type primary air manifold) greatly improves the change-out interval and allow easy nozzle replacement.

What are the next steps in the product development?

With industrial plants getting "digitized", requirements towards the critical plant hardware get higher. Outotec is actively providing digitization tools to our alumina calciner customers. We foresee a trend of having more accurate primary airflow for fluidizing and we are on the path to bringing more control and intelligence into the EasyNozzle design.


Mining Metals refining