Specification of Frederick Bowman : re-carbonizing animal charcoal.

  • Bowman, Frederick.
Date:
1857
Catalogue details

Licence: Public Domain Mark

Credit: Specification of Frederick Bowman : re-carbonizing animal charcoal. Source: Wellcome Collection.

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    Bowmans Improvement in the Process of Renewing the Virtues of Animal Charcoal. charcoal upon the drying plates, as that will depend on the degree of moisture on the animal charcoal, and many other circumstances ; all that can be said is, that the workman must not pass it on to the carbonizing plates L until it has become dry, or nearly so, and he must continually turn it over and over, 5 and stir it about with his rake while it is being dried, an essential object of the process being that, as nearly as possible, every particle of the animal charcoal shall pass over the whole length of the drying plates K and J so as to get dried gradually ; and also that, as nearly as possible, every such particle shall be exposed in its turn to the action of the atmosphere to evaporate its 10 moisture. It is only the carbonizing plates L which are nearest to the fire that are allowed to get red hod, and the fire should be so regulated as to keep them just red hot, and not much more. The animal charcoal which is brought on to the carbonizing plates L nearly or quite dry, requires only a little additional heat beyond what it will have taken up from the drying plates K 15 and J to decompose the animal, vegetable, or other decomposible matter which it contains, and to allow the escape of the gases formed by such decomposition. The animal charcoal must be constantly stirred about on the carbonizing plate L, as well as on the drying plates, to prevent it from getting quite red hot, which it ought not in general to do, although it may be sometimes 20 necessary to heat it to a red heat for a very short time. As a general rule, it must be exposed to the heat of the carbonizing plates until it gives out no more smell or visible vapor. This will generally be found to be the case when it is on the point of becoming red hot, but, as stated, it may be sometimes requisite to raise it actually to a red heat before it will cease to give out smell 25 or visible vapor, when it ceases to do so it will be recarbonized, so as to have recovered its whitening properties, and must then be immediately moved off of the carbonizing plates on to the plates F, and the workmen will tilt that up about its hinges to turn off the recarbonized animal charcoal from it into suitable receivers. Two workmen are sufficient to manage this furnace; the 30 most careful and intelligent should be employed to attend to the working of the animal charcoal on the red hot or carbonizing plates L, and keep it stirred, and clear it off thence on the plate F, and into the receiving jars, when it is completely recarbonized, and he must watch it very carefully, observing particularly not to leave it exposed to the heat of the said carbonizing 35 plates beyond the instant when it is carbonized, which, as stated, will be known by its ceasing to emit vapor and smell ; for if the animal charcoal be left to get red hot, and remain so for any time exposed to the atmosphere, its whitening properties will bo injured. Note. —The plate F may be made as above described, to move about hinge joints, or it may be