FLSmidth’s new Cross-Bar coolers offer benefits in terms of upfront investment, technical design and long-term cost of ownership. Torben Frigaard, FLSmidth, Denmark and K P Sathish Kumar, FLSmidth, India tell us about the latest development in cross-bar technology…FLSmidth launched its latest development in Cross-bar technology in 2011, setting yet another standard for clinker coolers called as the FLSmidth Cross-Bar cooler. The FLSmidth Cross-Bar is an evaluation of the design that grew out of feedback from having sold more than 230 Cross-Bar coolers representing a total installed capacity of about 300 million tonnes clinker per annum. The result is one of the most attractive cooler solutions available in the market – in terms of upfront investment, technical design and long-term cost of ownership. The FLSmidth Cross-Bar cooler replaces previous Cross-Bar cooler version to become FLSmidth’s one cooler offering for both new installations and upgrades.Benefits of the FLSmidth Cross-Bar coolerThe cooler uniquely provides a number of key benefits – something that no other cooler on the market today can fully demonstrate all at the same time??Consistently high thermal efficiency??High reliability and availability??Fast, low cost installation??Low, predictable maintenanceThe features that support above benefits are:??Separate clinker conveying and cooling systems – Crossbars effectively convey, mix and shear the clinker. Wear of crossbars has no effect on thermal efficiency of cooler.??A stationary, sealed grate line ensures no fall through and no requirement of undergrate clinker conveying system.??Self-adjusting mechanical flow regulators (MFRs) maintains constant air flow through air distribution plane and clinker bed without operator intervention results in stable cooler operation and high thermal efficiency.??Horizontal design with optimized transport method.??Modular concept:The FLSmidth Cross-Bar Cooler can be supplied for new coolers as well as to upgrade exiting coolers.Each unit measures 1.2 or 1.8 metres in width and 3.0 or 4.2 metres in length.Standard units are preassembled in workshop to ensure high quality and swift and simple installation.To form a whole cooler, a number of units are put together lengthwise and width wise and the movable frames are connected along the length of the cooler.??Cooler driveFast and low cost installation as hydraulic cylinders is integral to CB units.Each movable frame operated by two or four hydraulic chamber.No hydraulic components in first under grate chamber.Each drive has a separate motor and pump unit in closed loop system.Should one lane be taken out of operation, remaining movable frames can be kept in operation without stopping the cooler.??The cooler is erected on simple horizontal line foundation/support structure.??Access passagesFLSmidth Cross-Bar cooler has standard above-ground access passage across the cooler width which helps in monitoring under grate components during operation and provided outside access to the bearing lubrication points.??MaintenanceThe cooler has very few wear parts for easy and economical maintenance.Each cross-bar piece is installed with two wedges and pins and fully accessible from the over grate area and can be hand carried.The air distribution plate is two-piece design with the upper part removable and fully accessible from the over grate.??CrusherA standard at the outlet of the cooler, a heavy-duty roll breaker with modular frame design (HRB MF) efficiently breaks up the largest of lumps with its patented lower crushing roll arrangement and with minimal dust generation and noise.??ABC inletABC (Air Blast Controlled) fixed inlet gives an optimum start to the cooling process with a uniform clinker distribution, also eliminate the formation of "snowman".Through an internal check valve arrangement, high pressure air blaster air is allowed to eject through each and every gate plate to ensure there is no way for build-up and uneven distribution to occur across the inlet.Mechanical flow regulators for the normal cooling air, just like in the rest of the Cross-bar cooler, are still also maintained for every grate plate.Full flexibility in control of blasting area, blasting frequency and blasting intensity so that specific problem areas can be targetted.Retrofit possibilitiesWith its modular design, the FLSmidth Cross-Bar Cooler is flexible enough to enable complete or partial upgrades of most existing clinker coolers.Capitol retrofit case storyCapitol and FLSmidth have enjoyed a very close relationship, with virtually their entire San Antonio dry process plant run on FLSmidth equipment its start up more than 25 years ago. Despite their existing controlled flow grate cooler performing well, Capitol wanted to be prepared for a rebounding cement market once the recession loosened its grip in the US. So the FLSmidth Cross-Bar cooler was a natural first step towards greater capacity, while furthermore providing additional benefits such as higher thermal efficiency and lower maintenance. Within much of the existing casing, new cross-bar units were installed creating an eight-grate wide cooler rated for 2000t/d. The cooler has now been in operation for over 1? year and is in fact performing exceptionally well. There have been no unplanned kiln outage to date since the start-up, and the preliminary operational results are impressive with 20 per cent reduction in both standard cooler loss and fan power consumption.FLSmidth’s innovative and technological leadership is again demonstrated with the introduction of the new FLSmidth Cross-Bar cooler that seamlessly integrated into the rest of the pyroprocess.(Extracts from the proceeding of 12th NCB International Seminar on Cement and Building Materials held on 15-18 Nov ‘2011 at New Delhi)