Drying machinery and practice; a handbook on the theory and practice of drying and desiccating, with classified description of installations, ... glossary of technical terms and bibliography

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 edition. Excerpt: ...outlay, and requiring slight, if any, repairs. As means of drying by evaporation, all the floors have serious disadvantages as to heating, removal of the vapour, and handling. The heat when from above takes an undue time to permeate the mass, and from below has a cooking and caking action. The dispersion of the vapour in the first case is retarded by the cold body below, while in the second case it cannot commence till the mass is heated through, and even then the hottest part is not exposed, so all its vapour has to pass through the upper material. The handling obviously entails placing upon and removing from the floor, but owing to the uneven distribution of the heat it also entails the stirring up or turning over of the material one or more times if time and fuel are to be saved. The cost in space, too, has serious disadvantages where large bulks have to be handled and ground expensive. Of beating from above, haymaking is a good instance, and one in which the disadvantages are apparently unavoidable, while the sun's heat is free when available. Haymaking is also a good illustration of the governing principle of all drying installations, which is that the material governs the method of drying, and has to be considered more than mechanical efficiency. The nature of grass makes haymaking in many ways a particularly interesting case of drying. An artificial method of haymaking for use in wet summers is described under Dryingrooms (Gibb's). Briek drying by the sun's heat on earth floors has doubtless always been practiced more or less, but its disadvantages are so obvious that no modern brickyard would consider it, even if competition would allow. If sheltered from the direct heat and carefully placed to ensure even circulation, of course...