How does a lime kiln work?
The first stage in preparing this type of kiln was to light a coal fire at the base of the shaft. Alternating layers of coal and limestone pieces were then tipped into the charge hole at the top. Once the fire was lit and the fuel started to burn, there was no need for the bottom fire. It would keep slowly burning day after day with temperatures reaching over 900oC. As the powdery mixture, known as quicklime, dropped through the grate into the draw hole it was raked out and bagged. Further layers of coal and limestone were added at the top to allow continuous burning. The arched opening, known as the kiln eye, allowed air to feed the fire, prevented the hot quicklime from being blown around and protected it from the rain. There was also a poking hole to ensure the lime fell to the bottom. Producing lime this way was time consuming, dangerous and labour intensive. The material was corrosive and many workers suffered chemical burns from handling it or went blind if it entered their eyes.
