Vertical Kiln

Vertical kilns have among others the advantage of low investment profile and hence very suitable for small and medium scale processing of various solid minerals such as limestone. The low investment profile therefore makes it attractive in developing countries where sources of investment capital are lean. Vertical lime kilns however are plagued with a number of operational problems such as channeling, stratification, hanging accident, poor heat distribution among others. This work investigated the effects of burner types, firing rate and degree of draft on the vertical lime kiln temperature profile and hence the efficiency of the kiln. A pilot twin shaft lime kiln of 1.5 ton per day capacity was employed in the evaluation. It was shown that low firing rates of the burners affects negatively the kiln throughput and very low drafts lead to excessive backfiring of the burners. Many strategies were proposed to mitigate various negative phenomena experienced in the operations of vertical kilns.

The vertical  lime kilns have been shown to posses a lot of potentials in the lime industry and small scale cement industries. In view of the need to set up more small/medium scale chemical plans to meet with the local needs of chemical products like lime, the vertical lime kilns offers a good investment options. This is because of the following over-riding advantages shaft kilns posses over the rotary kilns.

• Low initial capital investment
• Low cost of operation
• Good flexibility of operations
• Low environmental pollution effects

Also the vertical shaft kilns because of its labor intensive nature is appropriate for developing countries where labor is cheap and unemployment rate is very high.

This work therefore seek to establish important strategies for operations of fired vertical lime kilns in order to achieve efficient operations which will ultimately encourage investments in vertical shaft kiln facilities. This is hoped will create multiplier effects that will catalyze growth of developing economies.