Designed to take the complexity out of installation and maintenance, FLSmidth’s new Hydraulic Roller Press concept has the potential to double capacity and significantly reduce energy consumption.
FLSmidth has released a new hydraulic roller press (HRP) concept designed to overcome some of the biggest challenges facing cement plants today. It features a compact layout, which is important both at greenfield installations and at plant upgrades, where limited space is an increasingly important design and construction factor.
Whether for raw material or clinker, an HRP is commonly used in pre-grinding processes as well as semi-finish and finish grinding arrangements. The technology enables clinker and hard brittle materials to be ground at high pressure.
FLSmidth’s new HRP achieves a grinding force of an impressive 6,500 kN/m2 for clinker and slag applications and up to 5,500 kN/m2 for raw grinding. The system features a latest generation, top-fed ROKS-H separator for clinker grinding or RAR-M for raw grinding. When used in semi-finish mode to an existing closed circuit ball mill system, it can deliver up to more than a 100 percent increase in grinding capacity while achieving an estimated savings of 30 percent in energy consumption.
Simplified concept for easier maintenance
FLSmidth’s newest HRP system concept offers a range of innovations designed to reduce civil costs, improve cement plant efficiencies and ease maintenance. The heavy components, such as the roller press, separator cyclones, dedusting filters and separators, are placed closer to the ground and towards the centre of the building, allowing easier access and reduced overall civil costs.
The HRP itself is also placed on an isolated foundation preventing vibrations from being transferred to the rest of the building. The feed bin can be moved relatively easily to one side for easier maintenance access. And, its user-friendly design has resulted in fewer components than previous designs, leading to greater consistency in performance, higher output quality, and reduced operation and maintenance costs.
High wear resistance
A critical feature of the roller press is the actual roller surface, which needs to be highly resistant to wear from clinker, slag or other material used for grinding, and should also have high resistance to tramp metals. FLSmidth’s objective is to reduce the wear rate, and for this, two types of surfaces are offered. The first is a hard-faced surface that can be rebuilt in-situ as required.
The second is the extremely hard TRIBOMAX® wear surface . The wear life of the unique 'Fit n forget' TRIBOMAX wear surface is expected to be minimum 25,000 hours in clinker grinding, and is likely to achieve up to 40,000 hours. TRIBOMAX® wear surface also has an outstanding resistance to tramp metals and oversized feed materials.
Avanish Karrahe, Global Product Line Manager of Roller Press Systems at FLSmidth, explains that an important aim in developing the new HRP was to create a much more efficient grinding system.
“The HRP includes several features that deliver much improved efficiency. We didn’t just want to achieve noticeable electrical energy savings, but ultimately also more consistent production levels, with less maintenance requirements,” - Avanish Karrahe, Global Product Line Manager of Roller Press Systems, FLSmidth
Metal detection has also been improved with a reliable and efficient metal detector. It detects all metal pieces down to 16 mm spheres, which restricts damaging metal particles from entering the system. This provides a safer working environment for the rollers, better feed consistency and more stable operations.
Avanish Karrahe explains how the HRP’s new concept overcomes an all-too-common problem: Anyone who operates a hydraulic roller press knows that angular misalignment can really lead to severe inefficiencies and mechanical damage to roller press rollers. So, we continue to use spherical roller bearings instead of cylindrical bearings, and oil lubrication instead of grease lubrication to address this problem directly. We have also improved the bearing house assembly to prevent oil leaks. He adds, “It is developments such as these that will significantly increase the expected lifetime of the roller press and lead to much more consistent operations.”
During its relatively short history, roller press technology has undergone significant development from a pre-grinding process to a range of applications including semi-finish grinding and finish grinding.
To date, FLSmidth has supplied more than 100 HRPs to cement plants around the world. Of these, six HRP systems have been sold since 2013. One is already in operation and three more will be in operation before the end of 2015.