IMPROVEMENTS IN THE MEANS AND APPARATUS FOR DESICCATING THE AIR SUPPLY TO FURNACES to be as follows:-
Year: 1885

page_text: I, CHARLES COCHRANE of The Grange, Stourbridge in the county of Worcester,
Ironmaster do hereby declare the nature of my said invention for "IMPROVEMENTS
IN THE MEANS AND APPARATUS FOR DESICCATING THE AIR SUPPLY TO FURNACES
to be as follows:-
"
In a Provisional Specification N° 14638 filed by me on the 5th November 1884,
I described a method of desiccating the air supply to furnaces wherein the air
before passing into the furnace or hot blast stove was submitted to the action of
solid calcium chloride, which, in taking up the moisture from the air gradually
assumed a liquid condition, and eventually required to have the moisture evaporated
therefrom in order to restore it to the solid condition so as to be again available
According to my present invention, instead of employing solid calcium chloride for
the above purpose, I employ a concentrated solution thereof, as I have found that
such solution, if submitted in a sufficiently finely divided condition, and for a
sufficient length of time, to contact with the air to be dried will act very effectually
in extracting practically the whole of the moisture therefrom care being taken as
was described in the case of the use of solid calcium chloride to submit the air,
when most charged with moisture, to the solution which has already absorbed the
largest quantity of water while as the air becomes more and more dry it is
submitted to the solution in a more and more concentrated state.
The apparatus employed for this purpose may be of various constructions, the
main object to be attained being to provide within a given space the greatest
possible extent of surface moistened with the calcium chloride solution, with which
the current of air is brought into intimate contact in a more or less finely divided
state, while, at the same time the arrangement of the surfaces should be such as not
materially to obstruct the current or blast of air passing through the apparatus.
Thus according to one arrangement, the apparatus consists of a vertical chamber or
tower in which sheets of suitable woven fabric are so disposed close together in a
more or less inclined or a vertical position, zig zag or otherwise, that the calcium
chloride solution will flow slowly down them while thin strata of the air to be
dried are caused to flow in the contrary direction in intimate contact with the said
surfaces. Or in place of sheets of fabric, ropes or narrow bands or rods arranged
either parallel to or crossing each other, and either vertically horizontally or

page_text: inclined, may be employed, the solution being either made to flow continuously
along the surfaces thus presented, or to fall in drops from one surface to the next
below, the air blast being made to pass through the shower thus produced as
well as in contact with the surfaces. The apparatus described in my said former
specification may be modified so as to operate according to the last described
method by substituting for the air-lock through which the solid calcium chloride
was supplied, a pipe conveying the concentrated solution on to a distributing
apparatus at the top of the desiccating chamber, such apparatus consisting either
of a series of finely perforated troughs from which the solution would drip on to
the gratings or bars below; or a Barker's Mill with finely perforated arms may be
employed for this purpose.
Apparatus may also be employed for the purposes of this invention similar in
construction to the ordinary coke scrubbers of gas works, namely vertical chambers
filled with coke or other porous material, or material offering a large number of
interstices, the calcium chloride solution being made to flow downwards through
such porous filling, while the air is caused to flow upwards through the same.
This arrangement would however have the disadvantage of offering considerable
obstruction to the air blast. The dilute calcium chloride solution issuing from the
bottom of any of the apparatus above described is brought back by evaporation to
the required degree of concentration and is then again employed for the same
purpose.
As the evaporation of the moisture from the calcium chloride requires pro-
portionally a much greater amount of heat during the last stages of the process
than during the first stages, it will be evident that a considerable economy in fuel
will be effected by operating according to the present invention as compared with
the method involving evaporation of the calcium chloride to the high degree of
concentration described in my former Specification.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.

page_text: I, CHARLES COCHRANE, of The Grange, Stourbridge in the County of Worcester,
Ironmaster, do hereby declare the nature of my invention for "IMPROVEMENTS
IN THE MEANS AND APPARATUS FOR DESICCATING THE AIR SUPPLY TO FURNACES "
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
In a Provisional Specification No 14638 filed by me on the 5th November 1884,
I described a method of desiccating the air supply to furnaces wherein the air
before passing into the furnace or hot blast stove was submitted to the action
of solid calcium chloride, which, in taking up the moisture from the air, gradually
assumed a liquid condition and eventually required to have the moisture
evaporated therefrom in order to restore it to the solid condition so as to be
again available.
According to my present invention, instead of employing solid calcium chloride
for the above purpose, I employ a concentrated solution thereof, as I have found
that such solution, if submitted in a sufficiently finely divided condition, and for
a sufficient length of time, to contact with the air to be dried will act very
effectually in extracting practically the whole of the moisture therefrom, care
being taken, as was described in the case of the use of solid calcium chloride, to
submit the air, when most charged with moisture, to the solution which has
already absorbed the largest quantity of water while as the air becomes more
and more dry it is submitted to the solution in a more and more concentrated
state.
The apparatus employed for this purpose may be of various constructions, the
main object to be obtained being to provide within a given space the greatest
possible extent of surface moistened with the calcium chloride solution, with which
the current of air is brought into intimate contact in a more or less finely divided
state, while at the same time the arrangement of the surfaces should be such as
not materially to obstruct the current or blast of air passing through the apparatus.
Thus according to one arrangement, the apparatus consists of a vertical chamber
or tower in which sheets of suitable woven fabric are so disposed close together
in a more or less inclined or a vertical position, zig zag or otherwise, that the
calcium chloride solution will flow slowly down them while thin strata of the air
to be dried are caused to flow in the contrary direction in intimate contact with
the said surfaces. Or in place of sheets of fabric, ropes or narrow bands or rods
arranged either parallel to or crossing each other, and either vertically, horizontally
or inclined, may be employed, the solution being either made to flow continuously
along the surfaces thus presented, or to fall in drops from one surface to the next
below, the air blast being made to pass through the shower thus produced as well
as in contact with the surfaces. The apparatus described in my said former
specification may be modified so as to operate according to the last described
method by substituting for the air lock through which the solid calcium chloride
was supplied, a pipe conveying the concentrated solution on to a distributing

page_text: Fig. 1 of the accompanying drawings shews a part elevation and part vertical
section of one arrangement of apparatus for treating air with concentrated calcium
chloride solution according to my above described invention A is a vertical air
tight casing of circular cross section, into the lower part of which, the air to he
desiccated is introduced through the branch pipe B¹ from the main pipe B, while
the dried air issues therefrom at the top through the pipe C. Within the casing A
are arranged a number of frames D D, constructed according to Green's Patent,
containing stretched sheets of canvas or other suitable fabric d d arranged in
vertical positions closely side by side between wood laths d', as shewn more clearly
in the enlarged elevation, cross section, and plan thereof at Figs. 2, 3 and 4, and
in the still farther enlarged detail at Fig. 5. These frames being supported at
bottom by beams D₁ and arranged side by side and one above the other as shewn,
offer very extended surfaces over which the concentrated calcium chloride solution
is made to flow downward, this being supplied through a pipe E to any suitable
arrangement of distributing apparatus, such as Green's distributor, shewn at F by
which the liquid is distributed uniformly over all the frames at top. Thus the air
in passing up from the pipe B' through the narrow spaces between the canvas
sheets, is brought into very intimate contact with the calcium chloride solution
flowing down them, and it will be seen that the air entering from B¹ containing
the full amount of moisture, will be brought in contact with the chloride of calcium
flowing down the lowermost frames, which has already taken up a large amount
of moisture, while in passing upward, the air will become more and more deprived
of its moisture until near the top it is brought in contact with the fresh calcium
chloride, so that by this well known action of reversed currents, the air will be
very effectually deprived of its moisture with a minimum expenditure of calcium
chloride.
The calcium chloride solution in a more or less dilute condition consequent upon
the moisture which it has taken up, collects in the bottom of the casing A and is
discharged thence by the blast pressure on the surface of the liquid through the
pipe G (or it may be withdrawn by a pump) in order to be evaporated down to
the requisite concentrated condition for being used over again in the apparatus.
H is a glass gauge for observing the height of the solution in the casing; I I are
manholes for gaining access to the interior thereof.
713

page_text: to
In the modified arrangement shewn at Fig. 6, the canvas surfaces J J, instead
of being stretched in small frames piled one above the other as in the above
described arrangement, are formed as continuous sheets extending from top to
bottom, being attached to stiffening laths K, which are secured by ropes
beams K fixed in the casing A as shewn more clearly at the enlarged detail
Fig. 7. The apparatus is otherwise of the same construction as above described.
Fig. 8 shews another mode of forming extended surfaces for the calcium chloride
solution to flow over. In this case wooden rectangular frames L L wound round
with rope M are supported at bottom by beams N, and are arranged closely side by
side and one above the other, being made to alternate in position as shewn more
clearly in the enlarged plan and side view at Figs. 9 and 10. This alternation of
the position of the frames may be variously modified and it might indeed almost
be dispensed with.
The rope is so wound upon the frames as to leave a small space between each
successive winding, thus forming narrow passages for the air blast to pass up
through while the calcium chloride solution supplied from the distributing
apparatus F, drips down from the ropes of one frame to those of the next below.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1, Desiccating the air supply to furnaces by causing a concentrated solution of
calcium chloride to flow. downward over very extended surfaces presenting small
spaces or interstices, through which the air to be treated is caused to rise so as to
be brought into intimate contact with the chloride of calcium solution substantially
as herein described.
2, Constructing apparatus for dessicating the air supply to furnaces wherein
a concentrated solution of calcium chloride is introduced into the top of a closed
chamber containing stretched sheets of canvas or other material, over which the
said solution is caused to trickle downwards while the air to be treated is caused
to ascend through narrow spaces intervening between such surfaces, so as to be
brought into intimate contact with the calcium chloride solution thereon, substan-
tially as herein described with reference to Figs. 1 to 7 of the drawings.
3, Constructing apparatus for desiccating the air supply to furnaces wherein
a concentrated solution of calcium chloride is introduced into the top of a closed
chamber containing frames upon which ropes or narrow bands are wound, with
interstices between the windings, so that as the solution trickles downwards over
the surfaces of the ropes or bands, the air to be treated, in rising up through the
interstices is brought into intimate contact with the calcium chloride solution
upon the ropes, substantially as herein described with reference to Figs. 8 to 10
of the drawings.