IMPROVEMENT IN PROCESS AND APPARATUS FOR DRYING BONE BLACK
Year: 1885

page_text: I, SAMUEL MORRIS LILLIE, of Philadelphia, Pennsylvania U.S.A. Chemist, do
hereby declare the nature of my invention for "IMPROVEMENT IN PROCESS AND
APPARATUS FOR DRYING BONE BLACK," and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My process consists first, in drawing or forcing the products of combustion of
the kiln through the wet black contained in suitable receptacles, the products of
combustion being first cooled to a degree by mixing them with cooler air or gases,.
so that the danger of igniting the black may be lessened; second in drawing warm
air from around the kiln through moist black contained in other suitable receptacles
by which the black is more or less dried and the air cooled and ladened with
moisture and in using the air thus cooled and moistened for mixing with and
cooling the products of combustion, as above set forth; and third, it consists in
collecting the steam generated in the drier and retorts of the kiln, and in using
the same for heating water or for heating or evaporating sugar solutions.
The apparatus consists of a drier located above the kiln and of exhausting
apparatus connected with the drier and with the retorts of the kiln for drawing,
air and products of combustion through the wet black in the drier, and for
exhausting the steam formed in the retorts from the same. It also comprises
suitable condensers for utilizing the vapors and steam drawn from the black in
heating water or in heating or evaporating sugar solutions.
The apparatus is illustrated in the drawings of which Fig. 1 is a vertical
transverse section of the drier along the broken line x, and of the upper portion of
the kiln along the broken line y Fig..2.
Fig. 2 is a side elevation of the drier and of the upper portion of the kiln, with
portions of each broken away to disclose the interior construction.
Fig. 3 is a horizontal section through the drier along the broken line 2, Figs. 1
and 2 while the other figures are views of details.
In the drawings, A is the fire-chamber of the kiln, having one or more rows of
retorts, R ranged on each side in the usual manner. B is a longitudinal Blue above
the fire-chamber, with which the fire-chamber connects by suitable flues (not
shown) containing dampers by which the draught of the fire is regulated. The
flue B is divided into two by the horizontal perforated diaphragm a, which tends
to distribute the products of combustion from the kiln equally among the tubes of
the surface-heater, presently to be mentioned. Upon the girders and the walls
of the flue B rests the bed-plate b, upon which is built the drier. The drier
consists of a surface-heater resting upon the bed-plate over a central longitudinal
opening in the same; of the channels D with perforated walls on each side, for
the black to be dried; opening above into a hopper E, and below through passages
in the bed-plate, provided with slides a, into boxes F, into which the upper ends,

page_text: of retorts R open; of the hoods J, covering the outside perforated walls of the
channels D; of the air-passages c c on each side, between the surface heater and
the black-channels D; of the vertical channel G between the end of the surface
heater and the front plate of the drier; and of the horizontal flue I between the
upper tube-plate of the surface heater and the plates of the hopper E, which flue
communicates either through the passage F, with an exhausting apparatus or with
a vertical channel G, depending upon the position of the damper n, which in its
normal position closes the passage f as shown. The surface heater consists of a
battery of tubes o, opening above and below respectively through the tube
plates, and contained in the chamber formed by the said tube-plates, the
vertical walls hh' extending from end to end of the drier, the rear end plate K
of the drier and the vertical partition extending between the partitions h¹ a
short distance from the front end plate L, of the drier. In the interior of the
heater are contained horizontal partial diaphragms v, through which the tubes
extend with a snug fit, the diaphragms being located equally distant from each
other and from the tube-plates i i¹, and touching alternately the end plates j K of
the heater, thus forming a longitudinally zigzag channel back and forth among the
tubes, the upper extremity of which communicates through the rear end plate K,
of the heater and drier with the mains M while the lower extremity communicates
with the vertical chamber G by an opening k, through the front end plate of the
heater. The rows of tubes O break spaces with each other in the direction of the
length of the heater, and the side walls h¹ bear vertical ledges r, which project
out between the rows of tubes, so that there are no unobstructed channels through
the heater longitudinally, as a result of which gases or vapors that are made to
flow along the zigzag channel of the surface heater must repeatedly impinge upon
and flow around it in contact with the heated surfaces of the tubes which form
the conditions the most favorable to the transfer of heat from the tubes to the
gases or vapors. Each tube o is closed above by a cap w, having perforations in
it, from the center of which depends a rod into the interior of the tube, on which
rod are slipped star-shaped pieces m³, (as shown in Fig. 4 which is a vertical axial
section of one of the tubes o) formed of cast iron, earthenware, or other material.
These pieces suspended in the interior of the tubes serve the purpose of absorbing
heat from the hot products of combustion which flow up, through the tubes, and
of radiating it to the walls of the tubes, by which it is absorbed conducted and
delivered to the moist air, which during the operation of the drier is flowing
through the heater along the zigzag channel, all as hereinafter set forth. The
advantage which the presence of such heat absorbents and radiants in the tubes
possesses arises from the fact that gases particularly when dry radiate heat, very
poorly and excepting through contact lose it slowly. By filling the interior of the
tubes with pieces of solid substances, especially with those which absorb heat
readily numerous absorbent points are presented to the contact of the gases by
which the heat is taken up from the latter and radiated to the walls of the tubes.
It is not necessary it is apparent, that the material should be shaped into stars or
be suspended on a rod as shown for other shapes and other methods of support
may be used without departing from the spirit of this feature of my invention.
Another end served by these heat absorbers is that of arresting the suspended
matter as contained in the products of combustion, and thereby preventing their
passing into the black when the gases are drawn through it as hereinafter set
forth. The perforated caps w which close the upper ends of the tubes, by limiting
the area of the passages for the escape of the gases from the tubes, tend to effect
an even distribution of the gases amoung the tubes, which is of course essential to
the most effective working of the heater. To this equal distribution the perforated
plate a in the flue B contributes as well as the caps w of the heater tubes o. The
hollow side walls of the drier are each formed of a framing consisting of the
vertical plates N, (which divide the hollow side walls each into four char-
channels D) and of the horizontal framing pieces of the front wall and t t¹ t³
of the inner wall. The divisional plates N and framing pieces t and devide the

page_text: outer and inner walls into panels, two to each channel D, which panels are each
filled with plates c¹, which rest in rabbets formed on the edge of framing pieces
and divisional plates, and which are held in position in any suitable manner.
These plates are each perforated by a number of horizontal rows of vertically
narrow slots a¹, and each bears on its inner surface a ledge or narrow shelf vl,
above each row of slots, which shelf prevents the black with which in practice
the space between the walls is filled from flowing through the slots. The
inclination of the shelf to the plates may be varied. On the plates of the inner
walls, through which the desiccation air or gases pass to the black, as hereinafter
set forth, the shelves may be vertical to the plates, and in case of the plates of
the front wall, through which the air leaves the black the shelves should be
inclined downward over their respective rows of slots as such a construction will
permit of a stronger draft of air through the column of black, without carrying
black through the perforations, than would be possible with shelves perpendicular
to the plates. The width vertically of the plates e¹ may be sufficient so that one
may bear all the shelves and fill the space of one panel; or on the other hand, the
plates may be only wide enough to bear one shelf vl and the corresponding
perforations; or in other words there may be as many plates e' in a panel as there
are shelves v¹, in which case the panel is filled in effect with a number of slats
supported at the ends and intermediately by bits of metal which correspond to the
plates e. If the shelves are made of sufficiently heavy metal to support the
weight or pressure of the black, they may be joined together or supported merely
at the ends, the spaces between the shelves being quite open. I prefer however
the construction shown, as it insures a more perfect distribution of the currents of
air through the black and for this same reason the perforations of the inner wall
are arranged so as to break spaces with those of the front wall both vertically and
horizontally Each of the panels of the outer wall is covered air-tight by a hood J
the lower set of hoods on each side communicating by a central opening in each,
and by the branch mains m and mains M, through the rear end of the drier, with
the interior of the surface heater above the upper partial diaphragm v, while
the upper set of hoods J, communicating through the branches p and P with the
large main S, which leads to an exhausting fan and condenser (not shown.) The
branch mains m and p are each provided with a gate g¹. The spaces between
the hollow side walls, respectively and the surface heater are each divided into two
compartments c c by the horizontal partition b¹ extending from end to end of the
drier on a level with the middle horizontal member t¹ of the side wall frame of
which compartments the lower one c on each side communicates through a main d
with the space underneath the flooring e, while the upper one c¹ communicates by
a passage s, through the extended heater walls h with a vertical chamber G at
the end of the drier which latter also communicates at the bottom by the passage /c
through the end of the surface heater, with the interior of the same below the
lower diaphragm v as hereinbefore described and above with the flue I, above the
surface heater supposing the damper n to be open, as shown in the drawings.
When this damper n which revolves on an arbor n² is lowered or closed the
communication between the chamber G and the flue I is closed and the latter
then communicates through the passage f with the exhausting main s, by which
the draft for the kiln-fire is then produced. The inclined plates O O¹ above the
flue I, and forming a part of the hopper E are each divided along a horizontal line,
and the parts hinged thus forming doors or wings which when thrown back
permit access to the surface heater tubes o. By means of a door T at the end of
the flue B access may be had to the latter. The mouths if the retorts R are
covered with a plate or plates d' having funnels o³, leading one into the interior
of each retort, and through which the black flows into the latter. In each retort
there is an annular space n¹ forined between the upper surface of the black in
the retort, (indicated by the dotted line in the drawings Fig. 1) the walls of the
retort and the conical funnels o¹. This space n¹ in each retort communicates
through a branch 71 and socket 8* (seen in detail Fig. 5) with the main W which

page_text: communicates through a surface or spray condenser C, and mains V P &c., with
the exhausting apparatus. The condenser C¹ is provided with a water or (sugar
solution) connection for condensing the steam brought to it through the main W.
When the kiln and drier are in operation the steam and gases which are generated
in the retorts rise through the black and collect in the annular space n from which
they are drawn through the manifolds W to the condenser C, in which the water
vapors is condensed by the water or sugar solution flowing through the condenser
with the effect of heating the latter while the incondensable gases are carried off
through the mains V P, &c.
The operation of the above described apparatus and the advantages of the
same may be set forth as follows, at first stating however that during the drying
and the revivification of the bone-black by this drier and kiln the retorts ŕ and
the channels D are always filled with black; that the black lies in the hopper E
and in the boxes F, as indicated by the dotted lines, and that there is a slow
movement of the black (which is fed into the hopper E) downward through the
channels D and retorts R, due to a uniform or intermittent drawing of the black
from the bottom of the retorts or rather from the cooler tubes with which the
retorts terminate below. Supposing now, the exhausting fans to be in motion the
products of combustion are drawn from the fire-chamber of the kiln into the
lower compartment of the horizontal flue B; thence through the distributing
plate a upward through the tubes o of the surface heater (surrendering during
their passage their beat to the arresters m² and to the walls of the tubes) into the
flue I; thence into the vertical chamber G, where it mingles with moist air, which
has been drawn warın from below the floor e, (under which collects air heated by
contact with the walls, coolers and other parts of the kiln and by the radiant heat
from the same) into the air passages c; thence through the black in the lower
portion of the channels D, partially drying the black and being itself cooled and
ladon with moisture; then through the hoods J, branches m, and mains M, into
and through the surface-heater, entering the latter above the upper partial
partition v, flowing back and forth around the partial partitions until it issues
from the heater below the lower partition into the vertical chamber G where it
meets and mingles with the products of combustion and with them flows through
the openings s¹, in the vertical partition h into the air passages c¹ and thence
through the black in the upper portion of the chamber D into the hoods J', and
then through the branches p, and mains P to the main S which leads to the
exhausting apparatus P and to a condenser P¹ (see Fig. 2) in which latter the
warm vapors with which the air and gases are laden are condensed by cold water,
which is heated to a degree thereby preparatory to being further heated and used
in the refinery. The uncondensed air or gases pass off by pipe Ps. The steam
formed by evaporation of water from the black while in retorts R is exhausted
from the retorts through the branches 1 into the cross main or manifold W;
thence through the condenser C in which it is used for heating water or sugar
solutions or for evaporating sugar solutions if suitably constructed evaporating
apparatus be substituted for the condenser C. The air and the products of
combustion in their passage through the black, as described evaporate and bear
away with them much of the moisture contained in the black, which in consequence
is comparatively dry when it passes from the drier into the boxes F and retorts R.
The desiccation is partly effected in the upper portions of the channels D by the
mixed air and products of combustion after which a further portion of the moisture
is removed by the warm air drawn through the same black while in the lower
sections of the channels. Any moisture remaining in the black after it leaves the
drier is driven from it while in the retorts R, the resulting vapor passing from
the retorts to the condenser C, as hereinbefore described. By means of the gates gl
in the branch mains m p the volume of air and gases drawn through the black
back of the various hoods may be regulated so as to cause the relative percentages
of moisture in the black issuing from the lower ends of the four channels D
in each hollow side wall of the drier to be anything desired, For example, if it
,

page_text: should be found that certain retorts of the kiln burn the black less effectively
than others, then the gates g¹ should be so set that more gases and air shall be
drawn through the black channels D which deliver black to these retorts than
through the channels which deliver to the more effective retorts as a result of
which the black which flows through the former into the less effective retorts will
be drier than that which flows from the latter into more effective retorts; and so
it is that by dividing the passages for the black in a drier into a number of
independent channels, and by having the desiccation in each channel under control
independently of the others, as is the case in this drier differences in the effective-
ness of the retorts in the kiln may be compensated for in the drier by properly
regulating the desiccation in the various channels.
My process contemplates and I prefer drawing the products of combustion
through the black, for thereby the heat in the same may be more comprehensively
utilized in drying black than by any other method that I know of and also because
the products of combustion have comparatively little oxidizing power, and are
consequently less liable to destroy the carbon of the bone-black by oxidization
than is the case with air heated to the same temperature. Should it occur however,
that the fuel being used at any time was of such a character that it would be
injurious to the black to pass the products of combustion through it the con-
struction of my drier is such that they may be passed from the drier in another
way than through the black and the heat in the products of combustion be utilized
only in heating air in a surface heater which heated air is afterward drawn through
the back. This may be done by lowering the damper n, (see Fig. 2), which closes
the communication between the flue I and the vertical chamber G and allows the
products of combustion to pass through the connecting main f to the exhausting
main S while the air which has been reheated in the surface heater by the products
of combustion is alone drawn through the black into the upper hoods J¹.
When
If a constant supply of a proper fuel-such as good anthracite-could be assured,
the surface heater might be dispensed with and the moist air from the lower
hoods J, be mixed directly with the products of combustion in a suitable chamber,
such as would be left by the removal of the tubes o of the surface heater, and the
mixture drawn through the black. When the products of combustion are passed
through the black, the draft for the kiln fire is necessarily an artificial one.
the products of combustion are only used in a surface heater for heating air to be
drawn through the black, the draft should also be an artificial one, if it is desired
that the heat in the products of combustion should be utilized in drying black to
the greatest extent possible, for otherwise the gases could not be cooled below the
degree necessary to produce naturally-i,e, by chimney the draft required for the
fire, while with an artificial draft the gases may be cooled to a much lower degree
and the heat utilized. The artificial draft in the latter case may be effected by
delivering air under pressure into a closed ash pit or by exhausting from above,
which exhaustion may be done by the same apparatus that draws the air through
the black, as exemplified in the drawings, or by independent exhausting apparatus,
such as a fan or a chimney of other furnaces that of the boilers of the refinery.
for example. One of the features of the arrangement of apparatus shown and
described which I claim as mine is that which permits this using, when the
products of combustion are not drawn through the black, of an artificial draft in
connection with the use of a surface heater, for heating air to be drawn through
the black, the merit of the arrangement being that the amount of heat which may
be absorbed from the products of combustion is not restricted by the necessity of
leaving sufficient heat in the gases to supply a natural draft for the fire, which
heat is in that case not available for drying black.
My method also contemplates as herein before set forth, the employment of air for
mixing with and cooling the products of combustion prior to drawing them through
the black, which having been drawn warm from below the floor e, is passed through
the partially dried black in the lower portion of the drier and thereby cooled and
laden with a moisture to a degree, the advantage of which proceeding will appear

page_text: from the following considerations. It is desirable to utilize the heat in the hot air
which arises from under the kiln and its cooler tubes and collects under the floor e,
as well as that which is contained in the hot products of combustion, and this can
be done either by drawing the air and products of combustion through the black
separately or by mixing the air with the hot products of combustion and drawing
the mixture through. If the first method is followed the ignition of the black and
the destruction of its carbon by the hot products of combustion may be relied upon
for although the products of combustion may be drawn with safety through the
black at a higher temperature than air, on account of their lesser oxidizing power
they cannot be thus drawn through at the high temperature at which they enter
drier without great danger. If the second method is followed,. there is still
imminent danger of igniting and destroying the black, particularly in the lower
portion of the drier, where the black is comparatively dry as the mixture will be
too hot to be drawn through the black without risk unless my system of first
abstracting and utilizing the heat from the hot air is followed, or unless an
excessive amount of the cooling air is used. Following my system the hot air
drawn from below the floor e. is not only cooled to a comparatively low temperature
by being drawn through the black in the lower part of the drier, but is also laden
to a degree with moisture abstracted from the black and in this condition has a
much greater cooling effect on the products of combustion when mixed with them
than before both on account of its lower temperature and of the added moisture
which latter also plays the part of a dilutant of the air and the mixture and reduces
its oxidizing power. This mixture can be drawn through the moist black in the
upper part of the drier without danger to the carbon and without having used an
excessive amount of cooling air. When the products of combustion are not drawn
through the black, but are used only in a surface heater for heating air to be passed
through the black, a similar advantage attends drawing the hot air from beneath
the floor e first through the black in the lower part of the channels D and then
through the surface heater-namely, that owing to its lower temperature and its
contained moisture, it will when heated by the surface heater, be of lower tempera-
ture, and be less likely to destroy the carbon of the black than would be the case
if drawn from below the floor e immediately through the surface heater.
important result of the presence of the moisture in the air in this case is that it
renders the latter more absorbent of radiant heat, and therefore more effective in
abstracting heat from the products of combustion in the surface heater, for as
is well known dry air and dry elementary gases cannot be heated by radiant heat,
but only by contact, but are good absorbers of radiant heat when moist; and so it
follows that by first passing the air through the black and moistening it the
radiant heat within the heater is made available for heating the air, and with a
given size heater a greater proportion of heat may be absorbed from the products
of combustion and utilized than if the air were not first moistened in this way.
The efficiency of the heater could likewise be increased by arranging
"heat
arresters among the tubes similar to those in the interior of the tubes, which
arresters would absorb the heat radiated from the tubes and give it up again by
contact or conduction to the air passing through the heater. The presence of such
heat arresters would be of especial importance were the air passing through the
heater dry, and therefore only capable of being heated by contact.
"
An
It is to be observed as an important feature of my drier that the hotter mixture
of the products of combustion and air and the reheated air when it is used by
itself, are only drawn through the black which is wettest and most difficult to
ignite namely, that in the upper portions of the channel D-while the cooler air
from below the floor e is alone drawn through the partially dried and more easily
ignited black in the lower portions of the drier; and it is to be borne in mind, in
connection with the above remarks concerning the destruction of the carbon of the
bone-black, that in proportion as more of the moisture of the black is removed
from it in the drier and less of it in the retorts R, the temperature of the products
of combustion as they enter the drier and that of the reheated air from the surface

page_text: heater will be higher as less heat will be absorbed from products of combustion in
the kiln and therefore the more perfect the desiccation in the drier the greater will
be the need for such precautions being taken as are to be found in this process and
drier to prevent the ignition and destruction of the carbon of the black by the
gases and air drawn through it.
As will have been observed separate condensers are used respectively for con-
densing and utilizing for heating purposes the vapors from the retorts R and those
from the drier, the reasons for which are that the vapors from the retorts consist
mostly of steam mixed with but little air and non-condensable gases, and are more
adapted for use in surface condensers and in evaporating apparatus than the vapors
from the drier, which are composed more largely of air and incondensable gases
and are better adapted for condensation in a spray-condenser, although they too may
be used in a surface condenser, if it is properly constructed; and further that
owing to the destructive distillation in the retorts of the organic matter in the
black which has been absorbed by the latter from the sugar solution, and to the
gases and tarry matters formed thereby it might be desirable at time to keep
the condensed retort vapors separate and by themselves. These vapors may
however be sent to the condenser for the drier at any time by stopping the supply
of the condensing liquid to the condenser C, in which case the retort vapors will
pass on from the condenser via the mains V PS to the condenser for the drier.
Owing to lack of room the condenser for the drier-vapors is not shown in the
drawings; but I judge that a mention of a condenser as one of any of the common
species such for example as the shower-condensers often used for vacuum pans,
adapted to the special conditions of large quantities of incondensable air and gases
mixed with the condensable water vapors will be sufficiently explicit. A condenser
adapted for use under these special conditions is illustrated, described, and claimed
in another and pending application, in which are also claimed certain features
common to the apparatus shown in that and in this application. It is thereforo to
bo understood that these features common to both, though unclaimed in this
application, are not abandoned by me.
Having now particularly described and ascertained the nature of my invention;
and in what manner the saine is to be performed, I declare that what I claim is :-
1st. The within described process of utilizing the heat in the gaseous products of
combustion from the char-revivifying kilns of sugar refineries consisting in drawing
the hot or partially cooled products of combustion through wet black to dry the
same, preparatory to passing it through the retorts of the kiln.
2nd. In a char-drier, the hollow walls D, for containing the char to be dried and
having perforated sides, chamber or chambers c, covering one face of each hollow
wall end having connections for bringing heated gases to them chamber or
chambers J, covering the other and opposite faces of the walls, and exhausting
apparatus connected by suitable mains with the chamber or chambers J, and
operating to draw air or gases from the chamber or chambers c through the hollow
walls and the moist black contained therein.
3rd. The combination with a char drier in which the products of combustion
from the kiln in connection with which the drier is used are employed in a surface
heater in heating air to be drawn through the black in the drier for the drying of
the same, of exhausting apparatus communicating with the flue or chamber such
as I, into which the cooled products of combustion flow from the surface-heater,
and operating to effect a draft for the kiln-fire independently of the temperature of
its products of combustion.
4th. In a char-drier, the combination of a central surface heater having vertical
flue-tubes with air-chambers char-channels and exhaust-chambers arranged symme-
trically on each side of the surface-heater in the order specified all connected and
working in combination.
5th. The combination with a bone black revivifying kiln and superimposed drier
operating on the principle described of the floor e, or its equivalent for retaining the

page_text: heated air which rises from around the various parts of the kiln conduits leading
from the space beneath the floor e to the air-channels of the drier and exhausting
apparatus operating to draw the heated air from below the floor through the said
conduits and through the channels and black in the drier.
6th. In a surface heater tubes which break spaces with each other in the
direction along which the matters to be heated flow through the heater in
combination with ribs r, parallel to the tubes and projecting from the side walls
of the heater among the tubes the effect of the combination being to leave no free
channel which the matters to be heated might flow and so avoid contact with the
surfaces of the heating-tubes.
7th. In the surface heater of a char drier the combination with the tubes in the
chamber through which the air and gases to be heated flow, of partial partitions v
which are parallel to the tube-plates, and which form the interior of the heater into
a zigzag channel, through which the air or gases to be heated are led back and
forth among the tubes, entering the heater-chamber through a port at one end of
the zigzag channel and leaving it through one at the other end.
8th. With the tubes o of the surface-heaters, the combination of a perforated
diaphragm a, in the chamber B from which the gaseous products of combustion
flow into the tubes of the beater the diaphragm operating to distribute the gases
more evenly among the heater tubes.
9th. The combination with the tubes of the surface heater of a char drier of
perforated caps w, closing the ends of the tubes and operating to cause a more even
distribution of the products of combustion among the tubes.
10th. The combination with the vertical flues o of a surface-heater of the
perforated caps w, rods u suspended in the interior of the tubes from the caps w
and star or other shaped pieces of heat-absorbing substances strung on the rod in
each tube, the pieces acting as heat arresters to absorb heat by contact from the
hot gases and to radiate it upon the walls of the tubes.
11th. In a char-drier constructed substantially as shown and specified, the
vertical divisional plates N dividing the hollow side walls through which the black
flows into two or more separate or distinct channels D, hoods J, one covering the
outer face of each channel opposite the lower air-channel c, hoods J, covering
respectively the outer faces of the channels opposite the upper air channels c¹, the
hoods J communicating through the mains M and branches m with the surface-
heater of the drier, and the hoods J' through the branches p and mains P S with
an exhausting apparatus.
12th. In a char-drier constructed substantially as described gates gl, or equivalent
devices, located in the mains or branches leading from the exhaust chambers of the
drier to the exhausting apparatus, by means of which gates the flow of air or gases
through the black back of said exhaust-chambers may be regulated as desired.
13th. In a char-drier operating substantially as described char-channels such
as D, formed with perforated sides or walls air chamber or chambers c on the one
side of the channels, hood or hoods J covering air-tight the other face of each
channel, the hoods of each channel being independent of those of the other
channels, exhausting apparatus connected with several hoods by suitable connecting
mains and gates g₁ or equivalents in the connecting mains by which the draft of
air or gases through the several channels, and consequently the desiccation of the
black in each may be regulated.
14th. In a char-drier located above a revivifying kiln and delivering char to the
retorts of the same in which drier the desiccation of the char is effected by passing
heated air or gases through it as it flows downward through the char-passages of
the drier char-passages divided into a number of vertical sections, each section
delivering char to a certain number of the retorts below and the combination with
each vertical section, of means—such for example as the separate exhaust pipes and
gates g' in the drawings; by which the draft of air or gases through the black in
each section may be regulated independently of the other sections the object of the
arrangement being to permit the regulating the degree of desiccation of the black

page_text: delivered to the different retorts of the kiln, and so to compensate for differences in
the efficiency of the latter.
15th. The combination in the construction of the hollow side walls or char-
passages D of a char-drier (in which drier the char is desiccated by passing currents.
of air or currents of air or gases through it,) of the vertical divisional plates N and
end plates L R horizontal members t t¹ t2 and 11 12 extending between the vertical
plates and dividing the two walls of the char-passages into panels, and perforated
plates e filling the said panels.
16th. In a char-drier operating substantially as described char-passages with
walls constructed in panels as set forth and hoods J, one covering each panel of
the outer walls of the char-passages each hood communicating with exhausting
apparatus through intermediate connecting mains or apparatus.
17th. The combination with the retorts of a char-revivifying kiln of plates d¹
covering the mouths of the retorts and having funnels o¹ projecting one into each
retort, nipples 1, and manifolds W, with sockets 82, the combination affording
means for collecting and conducting away from the retorts of the vapors formed in
the same.
18th. The combination with the retorts of a char-revivifying kiln, of a condenser,
conduits connecting the retorts with the condenser, and means for drawing the
vapors formed in the retorts through the conduits to the condenser.
19th. In a char-drier in which the products of combustion from the kiln-fire are
used in a surface-heater for heating the air to be drawn through the char in the
drier, the combination with the flue such as 1, into which cooled products of
combustion pass from the surface-heater of two flues or conduits such as f and G
one of which leads directly into a flue or main such as S leading to draft producing
apparatus while the other leads to the rear or induction side of the channels with
perforate sides in which the black to be dried is contained and of a suitable
damper, such as n¹, or its equivalent which may be operated to either send the
cooled products of combustion through one of the two conduits to the draft main
or through the other conduit to the rear of the char-channels thence to be drawn
through the char.
20th. The combination of a bone-black kiln and drier, two condensers one
connected with the drier by suitable mains and the other with the retorts of the
kiln by other suitable mains and proper exhausting apparatus or equivalent means
for drawing the water vapors evolved in the drier through its condenser, and the
vapors generated in the retorts through their condenser the object of the com-
bination and of separate condensers for the drier and for the retorts.
21st. In a condenser used in connection with a bone black drier for condensing
the water vapors from the air or other permanent gases passed through the black
in the drier for drying the same the combination of an induction porte for the
vapor ladened gases, connected with the drier by suitable mains; an eduction
porte for the escape of uncondensed air or gases; induction and eduction portes for
condensing water or other liquids; and suitable internal devices for utilizing the
liquid for the condensation of the vapors from the gases during their passage
through the condenser.