In the best days of the so-called Jamaica Trains in Demerara, three-quarters of a ton of coal in addition to the megass was burned per ton of sugar made, and with this for many years planters were content, because they pointed to the fact that in the central factories, then working in Martinique and Guadeloupe, with charcoal filters and triple-effect evaporation, 750 kilos of coal in addition to the megass were consumed to make woo kilos of sugar.
Taylor bag filters are generally used for clearing the melted liquor of its mechanical impurities.
They have a false bottom, with cloth or gravel filters.
Plants are the best natural air filters.
In diffusion plants the milk of lime is added, in proper proportion, in the cells of the diffusion battery, and the chips or slices themselves act as a mechanical filter for the juice; while in the Sandwich Islands coral-sand filters have been employed for some years, in addition to the chips, to free the juice from impurities held in mechanical suspension.