Target net zero-optimising roller press performances: Kaushik Ghosh, Köppern GmbH & Co KG

Thank you, Tom, also for giving me this opportunity to speak here. Thank you, David, also for giving me this opportunity to speak here. And I was supposed to start at 10:00, now it's 10:20, so. I wanted to say so much of things, but I forgot. You know why? Because of the fact my superboss is here, the Manning director, and maybe I forgot something, but I will try to manage. So let's see how I do it. So what you see, it's a roller press, but not a normal roller press. It's a Köppen roller press. It's an engineering marvel, I would say, because 128 years, we are the oldest company. 128 years, we did nothing but roller press. We are small.

I take the cue from Alejandro that maybe some people doesn't know me or doesn't know my company. So we are the oldest roller press manufacturing company in the world, originated from Germany, from the rural region, and still it is owned by the same family which started the company in 1898. The next generations are taking care right now. So the topic is known, you have seen and also Tom has mentioned, target net zero. There was good presentations since yesterday and, also Peter mentioned that SCMs, McKinsey also mentioned SCMs is a way to go ahead. And Peter also made an survey yesterday where 40% of the people in this auditorium said that SCMs is the future.

There are CCAs, CCUs, but SCMs is the future. As I'm doing this presentation in Thailand where the grinding especially, it's a very old plant and especially done with roller press. And as I've said, we did 128 years this thing, so I will focus my presentations on roller press performances. Clinker factor. Everybody knows clinker factor needed to be reduced 50%, 60%, and you can see how it was in 2003 and what should be in 2050. But that is a report from 2010. Right now, we are talk at something around 50%. SCMs. So where do we put the SCMs? We have to use SCMs, but the SCMs is used mainly in the grinding sections.

So clinker is being produced by alternative fuels or petcoke, something, and then in the grinding sections, you are adding the SCMs, for example, the s**g, the fly ash. Fly ash is not coming to the roller press, especially the dry fly ash, but the pond fly ash is being put in the roller press. Now, the roller press technology itself is a physical thing. There is nothing chemical. The machine is designed based on the bulk density of the feed material, the particle size of the feed material, and the wear surface is being chosen and so on. So everything is happening in the roller press is physical.

These machines in Thailand or most of the plants in the world came out between 1990s, '86, and so on, or after 1986 and 1990s. So these machines were designed for a different kind of feed material, not for SCMs. What do I mean by different kinds of feed material? Because the particle size distributions has changed, and you know that. You are from the industry. So SCMs, when you do, you need to go for a higher fineness of the product to get the strength later on. So once you go for the higher fineness of the product, that means you're getting more fines onto the roller press. And it's very clear to all the roller press users how the roller press behaves in those situations.

So the challenges are there, and there was also yesterday, I could see a presentation from McKinsey. It was mentioned SCM is the future and upgrades also is the future. So to take care of these existing challenges, what I mentioned, the particle size distribution has changed, the density has changes, and the abrasiveness of the feed material has also changed. So what do we see? We see a higher wear on the roller surfaces. So if my car tire is not having the right profile, I'm getting an accident. I cannot go for higher speed also. Increased maintenances and reduced outputs. And reduced outputs means increased energy consumptions. That is very clear.

And we are talking about the existing machines which was supplied back in the '90s, back in 2000s. Everybody's not building up a new plant for SCMs. So SCMs should be to be used, but how to use it, and these are the challenges. Operational disturbances and reduced outputs due to changes in the physical properties. It's very clear with this. So what needed to be upgraded? What are we telling to upgrade? Customized wear protection systems, Hexadur and Circadur, the roller surfaces. New feeding systems adaptable to the different types of feed materials. Open loop hydraulic systems.

And as coming back to the McKinsey once again, is he mentioned that the upgrades should be around 3% to 5% of the OpEx, and that is true. And what we have seen is a faster than new equipment investments. It's quite faster. You don't need a separate layout or a separate building. Less CapEx, easy implementations. Normally, these upgrades take, for example, for the feeding system, for the hydraulic system, three to five days, and you are starting the machine once again. Reduced OpEx.

Obviously, if you get the rollers or the forces in the right way, so you have a reduced maintenance cost or zero maintenance cost from the roller press itself, and quicker return of investments because of improved performance of the roller press of the grinding circuits. HexaDuo, I think most of the people from the tire industries, I have very good customers, SCC, SCG, Asia Cement is there. They are using this HexaDuo since long time now. So average lifetime we have achieved from this HexaDuo surface is around 60,000 to 70,000 hours, and that too with zero maintenance. I mean zero. Zero. And there is no maintenance being done.

And it's been proved not in one locations, but many locations all over the world. HexaDuo is patented by us, is made by powder metallurgical techniques. But I'll not go detail onto it because I want to focus on SCMs and how to take care on the process performances. These are the various... You can see from the photos, that's how the surface looks like, and after 62,000 hours, 70,000 hours, and the wear rate. And normally, typical thickness of the HexaDuo tiles, it is custom-made as per your applications. And it is something around starting from 17 millimeters to 30 millimeters we have supplied till now.

So if the wear rate is 1.3 to 1.8 millimeter per 10,000 hours, you can yourself calculate the life of the rollers. There is one specific photo, I have put it over there. Oh, sorry. So this one, you can see the HexaDuo tiles is damaged. So we are running a cement industry. Foreign metals will come in. So in normal situations, what happens is the foreign material comes in, it generates some micro cracks, and because of this, there's a chunk off going on, and the roller surface is damaged and maintenances. With HexaDuo, these tiles are individuals being fixed with a special technology. And if the metal is coming in, yes, we also get damage, but the damage will be localized.

But we do not recommend any kind of maintenance to be done. We keep it like that and it goes on operation. But that doesn't mean that we can grind off big pieces of steel also. Then I'm against physics. I'm lying here. So yes, metal can go in, but it doesn't mean that it has to be full of material, because if it's s**g, we know there is a high risk of metal passing through the rollers. We have another solution, CircoDuo. It's not another name for stud rollers. The technology is similar, manufacturing technology, or the basic principle is same like the studded. So where we have the pins, the set pins are being fitted onto a normal forged sleeve or normal steel.

And we want this feed material to stick to the surface, giving an autogenous protective layer. Now, why did we send-- Because we are also manufacturing studded surfaces for all industries. We are shifted, or we have developed this product from CircoDuo from studs. Why? Because of the fact in the cement industry, we know, all of us know, that we need some specific pressing forces. So normally when we are doing clinker grinding, OPC, CEM I, CEM II, it's between 5,500 to 6,500 kilonewton per square meters. But when we are doing SCMs, like 100% s**g grinding, you need higher specific pressing force. And we have seen it should be between 4,500 to 5,000 kilonewton per square meters.

But when you are more than 3,500 or 4,000 kilonewton per square meters and operating a studded roller, what happens is the pins breaks. And once the pins break, the material, what I said, is not sticking to the surface. I mean, the feed material, the interstitial material is not sticking to the surface. So once it is not sticking to the surface, what is happening is it's a normal steel and it will wear out. That means I have seen many locations, the studded surface is changed over to an welded surface within couple of years, two, three years. This one is operating in a plant in Germany since 2021. Till now, five years in operations, and I expect another six to seven years of operation.

So long life, and also a zero-maintenance surface. Now the topic is feed systems. Everybody talks about choke feed. So what is choke feed? Choke feeding is we have uniform distributions of material along the roller working bit, and the material which is coming between the rollers should be free of any air. But SCMs, more fineness, that means more air coming between the rollers. So if you have more air coming onto the rollers, then what happens is you get problems. So there is a nice line over saying that, "Never operate at static gap." I know the roller press users knows what does a static gap.

So machine is being set to a static gap or a zero gap, depending upon the machine conditions, and then the feed material comes in and you achieve a operating gap. Why operating gap? Because of two nice formulas. Number one is throughput. And you can see here, as for physics, the operating gap is directly proportional to the throughput. And who is making the operating gap? The operating gap is made by the material. And if there is air inside it, so you're not getting the operating gap. And that is being seen in many audits what I have done all over the world. The operating gap is not there, or you're not achieving the required or designed operating gap.

So if I cannot achieve my designed or what is being designed working gap, then I'm missing my throughput. And on top of it, there is another formula which is called the bed pressure. Oh, sorry. The bed pressure. Bed pressure is the maximum pressure at the smallest gap. So it is given by a very nice formula, C, which is the machine constant, multiplied by the operating pressure, divided by the square root of the operating gap. So if I am operating with high pressure, there was a colleague yesterday asking me about high pressure applications.

So if you operate at high pressure, and you do not have the right feeding systems, which is giving you the choke feed or taking out the air, that means your dynamic gap or the working gap is compromised or going down, and you go up with the high bed pressure. So what happens with the high bed pressure is the force, specific pressing force, what is being given by the hydraulic pressure, it is not going to the material. You are not achieving higher fineness, but you're creating more problem onto the machines. That means more wear, damage on the bearings, gearbox, and so on and so on. So I think I could explain to you the importance of the working gap.

I always tell all my customers when I make an audit, I say that operating gap is like the pulse of human body. So if I go to a machine, I look at the machine and see that it is not operating at the right operating gap, then I know everything is not going in the right directions. This curve is not made from my head. So on the X-axis, we see the gravity feeder opening, our gravity. I'll explain to you in the later slides what do we mean by that. The opening of the gravity feeder is increased, and we can see that the output, which is through the blue line, you can see the output is getting increased because I explained to you over the formula.

And once the output is increased or the throughput is increased, my energy demand is going down. These are the different types of feeding systems available in the market by others. And unfortunately, none of them provides the right choke feed system because it misses the material flowing into the center of the rollers and not moving sideways. I can go in detail of it once you come to my booth, and I can explain to you. But these are the types what we have already replaced.

So what does a Kopan feeding system-- What we are doing is you have the feed belt, then you have the bin, and you can see that the bin center line and the gravity feeder center line and the rollers, sorry, the press center line is on the same lineal. So the material which is coming here, it is just flowing in one directions. And here you have maybe five or six meters, depending upon the design of the plant. And when it comes down here to the feeder opening, the walls, it is something between 200 to 280 millimeters. So the material is slowly coming down to the center of the rollers.

It is not moving sideways because what I have or we have seen, if the material is moving sideways, you are bringing more air onto the system rather than taking out air. In addition to that, what we are doing is, with our feeding systems, we are also supplying the check plates with a special truss bolt spring-loaded arrangements. So what we have seen is that if the check plates are not right, I have a customer here. So we supply the check plates, and with our only supply of check plates, they achieve 10% more productions from the plant. And it's being not proved in one plant, but many plants or all the plants, I would say. So how does our feeding systems look like?

So you have two walls Which can be moved, or we have in the background, there's control systems, and it is done automatically. It is not dependent upon the intelligence or the experience of the operator. Because we from the cement industry know that in some shift, the machine behaves very nicely, produces the right output. In some shift, it is not producing. So somewhere, we are dependent on the knowledge and the experience of the people. But with our feeding systems, with the controller at the background, when you press the button auto mode, it is doing on its own the adjustment. And what adjustment is it doing? It is adjusting the walls of the feeder as per the particles size distributions.

It is not looking into particles size distributions. It is looking into the kilowatt and/or the friction factor, which is the target, and then it is automatically changing. So this can be changed. The wall can be changed from the minimum to the arbitrary, because we know in some situations what happens is one roller takes higher kilowatt than the other, so there's a possibility to shift the material from one roller to another, and the maximum. So wide range of flexibility. In addition to that, as I've said that there is also another potential of upgrade is the open loop hydraulic systems. In our open loop hydraulic systems, the pressure is constant.

We are not regulating the pressure with solenoid valve. Solenoid valve is a time-dependent valve. We are regulating the pressure with a proportional valve. So what we say is if you control the pressure, that we say is plus minus two bar, you control the specific pressing force, you control the output of the machine. And that's also being done and proved also, but I'll not focus on that. Maybe in the-- So this is another slide which I have prepared to show that also in the non-Kopan machines, you can see the press frame is different than the others. So there also we did it, and it's been in operation since, let's see, January I commissioned that plant.

So minimum gap, arbitrary, and the maximum. Experiences. I can read it loud. Production more than 33% achieved, power drawn by the rollers more than 50%, and energy demand went down only by changing the feeding system. That's what we have achieved, not even the rollers. So there's a nice curve trend from one of the plants where you can see before overhaul, before changing to the feeding systems, the kilowatt drawn by the roller press was something around 1,000, 1,200 kilowatt. After overhaul, the kilowatts, you can see it's very clear from this graph. Before upgrades, how does the machine look like?

This one is, you can see there's leakages from the cylinders, and if you have leakages from the cylinders, you're not controlling the pressure. With the different kind of feeding systems, this kind of situation. So not only the production going down or your control on the machine is gone, but also you face environment problems. And in some countries, it is not even allowed for such kind of leakages. This is how the machine looks like after upgrades with our feeding systems. I had to take out the name of this company with the supplied or the OEM of this roller press.

So the earlier photo was with the leakages, and now it's been in operation since 2016 with the new hydraulic systems and the feeding systems, and a satisfied customer base. You can see here. So it's not only one plant, it's all the plants where we have done these upgrades. We have positive references. It's not much. We are a small company, not much people are knowing, but when they got interested, they're doing it, they get this positive advantage. So number of upgrades, what we have done on the Kopan machines. So the gray is the feeding systems. The hydraulic system is in the blue. So on the Kopan machines, around nine.

In non-Kopan type one, I will not name the OEM, around eight, six plus two. Non-Kopan type two is two feeding systems, one hydraulics, and non-Kopan type three is four feeding systems and two hydraulic systems. So that brings to the end of my presentations. And obviously, you will have questions. And you must have also received this one from Cemtech. And Tom, very nice, thank you very much. He gave me an opportunity to write an article. So if you go to page 60, you will find an article on this. So please go through it. Or if you want to talk to us, I have in the booth two very experienced gentlemen.

So one is Khun Polyo, who is the plant manager of Asia Cement in Poklang, and he's working with us since 2021. So he can share his experiences with you. And obviously, Dr. Develdegere, who's the managing director technical, and he'll be happy to answer your questions. So my booth is located outside, booth number 31. I'll be happy to come down to me, or you can invite me to your plant to have some further discussions. So that brings to my presentations. I think I didn't overdo it, but okay. I'm allowed little bit sometimes. So, Sawasdee Kub. Khop Khun Kub. Thank you very much. Thank you.