The Arabian Cement Company in Ramilya, Egypt was pushing the capacity of its SF Cross-Bar® Cooler to keep up with customer demand. But the elevated temperature of the clinker began harming cooler downstream equipment and affecting clinker grinding in the cement mills. FLSmidth suggested a simple upgrade that took place during the plant’s normal maintenance stop and didn’t require heavy equipment.
Business is good in Ramliya – so good, in fact, that Arabian Cement Company used to have a challenge keeping up with customers’ demands.
For quite some time, they’d been successfully pushing the capacity of their SF Cross-Bar Cooler considerably beyond the 6,000 tpd for which it was designed. But unfortunately, they were having a problem with the elevated temperature of the clinker harming the cooler downstream equipment and affecting clinker grinding in the cement mills if used directly. Nor were they able to achieve the throughput they truly desired.
“Before the retrofit, the cooler limited the kiln throughput to around 6,200-6,300 tpd,” says Fernas El Hakim, General Manager, Arabian Cement Company.
The plant had considered a variety of different ways it could boost capacity, including changing the cooler drive hydraulic pumps to increase the speed. But after thorough discussions with FLSmidth’s R&D and pyro experts, Arabian Cement Company recognised the merits of an upgrade plan.
- Greater throughput/capacity with the same grate area
- More cooler control under heavily loaded conditions
- Fewer cast parts for low, easy, predictable maintenance
- Longer lifetime of wear parts
- Improvements in thermal efficiency and power consumption
- Fast, simple installation
- Attractive investment level
An advance in technology
FLSmidth’s R&D staff surveyed the cooler and suggested a surprisingly simple upgrade that gives increased clinker transport efficiency, allowing greater throughput and more control of the clinker bed under heavily loaded conditions – all with fewer wear parts.
“My impression was generally positive, and I saw no harm in trying it as we could always return back to the original design if we failed,” says Fernas. In fact, he adds, “Now we can work normally in the range of 6,600-6,700 without toil if we have other stable conditions. We even hit the 7,000 tpd mark, but of course with higher temperature.”
FLSmidth’s approach included a thorough review of all existing pyro equipment from both a mechanical and process perspective before making a recommendation. “If the customer has other, additional requirements, we can perform that work as well. We always form a complete picture of the entire setup and make whatever changes are necessary to get an optimal result,” says Peter Green-Andersen, Senior Technical Advisor, Pyro Processing Systems, FLSmidth.
Quick, painless process
The upgrade was achieved with the majority of Arabian Cement Company’s SF cooler untouched. Essentially, it required only a change in cross bars and the hydraulic system – a “simple and quick” process, according to Fernas.
With the upgraded transport mechanism a shuttle drive motion is used, where all cross bars move forward together, and alternative lanes of newly designed two-wide cross bars move together in the reverse stroke. Because each cross bar covers only two grates instead of four, it is possible to achieve more finite control across the width of the cooler.
Furthermore, while the SF cooler normally has six moving and six stationary cross bars, the upgrade has only six moving cross bars along the length of a module.
In practice, this required changing the cross bars and dividing the drive frame into two separate, independent drive plates. By increasing the clinker transport efficiency with the same hydraulic flow volume and with fewer strokes, it is possible to achieve greater throughput without enlarging the grate area. And since the drive now moves more slowly, the lifetime of wear parts is also extended.
“The solution they originally were considering would have worn out the wear parts three times faster than what we ultimately proposed,” says Mads Jespersen, General Manager, R&D Product Development, FLSmidth.
It has fully lived up to our expectations.
|Sloped SF Cooler designed for 6,000 tpd|
|Sloped upgraded SF Cooler handling 6,800 tpd|
The upgrade took place during the plant’s normal maintenance stop, and no heavy equipment was needed to carry out the changes.
Following the upgrade, production increased from approximately 6,200 tpd to roughly 6,800 tpd, while helping sustain the good process performance with the increased production.
What’s more, Arabian Cement Company was so pleased with the results that they decided to upgrade an additional SF cooler to the new-and-improved technology. Another, similar facility that closely followed the plant’s progress also decided to do the same.
“It has fully lived up to our expectations,” says Fernas.