about RSP calciner

From your data it sounds like a host of possible root causes need to be analysed. From afar, it is difficult to say.

You mention a CPAG grate cooler, so I assume tertiary air duct, maybe the temperature coming to the calciner section is not high enough. From the CO values, it seems to be also a problem of O2 level at kiln inlet. Since FO is burning but anthracite is not, maybe the anthracite is too coarse, or not being well distributed into the calciner. Just some possible directions to investigate.

The RSP (Reinforced Suspension Preheater) pre-calciner was developed, as far as I know,  by Taiheyo in Japan. It is very well suited to burning alternative solid fuels in a stable operation due to its swirl chamber design.

One company that offers this design under license is A TEC (www.atec-ltd.com).

I hope this helps.

Sir,

We are having a very good alternative to fire the lowgrade coal/alternate fuels in the calciner. We offer the calciner named SLC-D which will overcome the difficulties you have mentioned. Please revert in case of any futher clarifications to me.

Sabeer Ali - FLSmidth.

sam-in@flsmidth.com

The RSP calciner is characterized by a combustion chamber (top - down gas flow) which is connected to the calciner just above the orifice. The combustion chamber consist of a swirl chamber with a burner in the roof section and 2 tangential inlet. Tertiary air is fed to the burner for flame control and into the tangential inlet for creating a meal curtain around the chamber body for refractory protection. The meal for the meal curtain is fed from the second last bottom stage stage cyclone.

The RSP calciner is refered to as a hot spot calciner as due to the control of the tertiary inlet at the centre burner a hot flame temperature can be achieved in excess of 1300 °C or higher limited only by the max. permissable refractory lining temperature and protective meal curtain respectively.

The meal and combustion gas mixture from the RSP hot spot combustion chamber is fed into the lower in-line calciner section which is designed as a mixing chamber mixing kiln gas with combustion chamber gas.

This is in a nut shell the design features of the RSP calciner.

The advantage of a RSP calciner compared to an in-line calciner is the increased stable temperature of appr. 1200°C in the combustion chamber to 870°C in the calciner and higher oxygen level from the tertiary air compared to a mixed combustion gas of tertiary air with kiln gas as will be available in the calciner.

The disadvantage of a seperate line calciner in comparison to an RSP combustion chamber is the tendency of blocking the lower section by dropping hot meal due to gas fluctuation and lower calciner temperature.

Combustion in existing calciner may be improved to a certain extent by extension of calciner section (increase of retention time) or stagged meal feeding thereby creating limited hotter combustion areas.

In any case you should get an experienced pyro-process specialist looking at all options i.e. RSP-calciner, stagged meal feed, calciner extension or seperate line calciner. A company secialised in such investigstions and upgrades and has experience with RSP calciner is ATEC.

 However your problem by the way I read it is the inefficient combustion at the main burner and this is the main problem you have to solve first.