Cement producers are constantly seeking new approaches to improve the profitability of their operations. For this purpose, FLSmidth has launched the next step in top-stage cyclone technology, the Down Draft Cyclone – called the DDX cyclone.
The DDX cyclone is a new development from FLSmidth, taking advantage of well-known cyclone technology from other industries and implementing it as part of the preheater in a patent-pending installation.
The project teams from Ivano-Frankivskcement and FLSmidth prior to the upgrade project
The DDX cyclone benefits
The raw material and preheater gas is mixed in the riser before the cyclone, and it is here the heat exchange occurs. In the DDX cyclone, the gas (red) and material (green) follows a down draft flow as indicated in the figure above, without changes in flow direction. This principle has proven to provide a low-pressure drop across the cyclone while maintaining a high separation degree.
The DDX cyclone is an ideal product for upgrade and modernisation projects, where production increase or reduced power consumption are project drivers.
In upgrade projects, the loads exerted on the preheater structure by the cyclone often restrict selection, meaning that it is not possible to install the most productive top cyclone. The dominant load from a top cyclone is the dust load, occurring if the cyclone material outlet is blocked. Due to its design, the DDX cyclone dust filling load is 50-60 percent less than for a traditional cyclone.
Together with its new lighter lining concept and fewer steel parts, this allows for selection of a significantly larger cyclone size compared to the traditional top-stage cyclone. For example, the new DDX cyclone design allows for a cyclone diameter that is approximately 20 percent larger without increasing the load on the existing preheater structure. This reduces top-stage pressure by approximately 10 mbar, which can lead to either increased production or reduced power consumption.
Flow patterns of gas and material in the DDX cyclone
The DDX cyclone can be lined, lifted and installed in one piece, minimising installation time and cost.
The DDX cyclone has been installed at Ivano-Frankivskcement in Ukraine following the cement plant’s evaluation of the new technology, in which the benefits of the DDX cyclone were clearly evident. The new cyclone was brought into operation in less than seven weeks.
The fast decision process, fabrication and installation were made possible through a close and long-term cooperation with Ivano-Frankivskcement that began back in 1998. This includes two production lines at the plant provided by FLSmidth in 2006 and 2013.
Together with other kiln modifications, Ivano-Frankivskcement experienced a clinker production increase from 2600 to 3100 tpd after installation of the new DDX cyclone due to a reduced pressure drop, while at the same time maintaining a high separation degree. Since the commissioning of the DDX cyclone, the cyclone has proven to provide stable, reliable operation.