Improvements in Apparatus for Evaporating and Incinerating Spent or Used Alkaline Lyes or similar Waste Products.
Year: 1892

page_text: Date of Application, 5th Jan., 1892
Complete Specification Left, 11th Aug., 1892-Accepted, 24th Sept., 1892
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Evaporating and Incinerating Spent
or Used Alkaline Lyes or similar Waste Products.
I, ALFRED SOMMERVILLE CALDWELL, of Greenfield Lodge, Lasswade, in the
County of Mid Lothian, North Britain, Paper Maker, do hereby declare the nature
of this invention to be as follows, that is to say :-
My said invention has for its object to effect the evaporation and incineration
of spent or used alkaline lyes or similar waste products in an improved manner and
more expeditiously than heretofore, so that plant of moderate size is enabled to
deal with larger quantities in an economical manner.
My improved apparatus comprises a furnace chamber in which, or in one part
of which the incineration takes place, also what is known as a "splash" chamber
in which the liquor is by paddles or equivalent mechanism, thrown up into spray,
and also a chamber or space which has in connection with it a fan or blower
employed to rapidly draw the hot gases through the splash chamber and in contact
with the spray and to remove the gases and vapors. The alkaline or other liquor
after having as usual been more or less heated or concentrated is run into the
splash chamber; from which the concentrated liquor is transferred to the furnace
chamber, by preference in the form of spray or in a number of small jets, which
may be produced by means of paddles or pumps or otherwise.
In the splash chamber screens are arranged to obstruct the passage of the spray
in the direction of the current of gases; and at the end furthest from the furnace
there is constructed a chamber which may be in the form of a tower at or over that
end of the splash chamber, of a size large enough for the velocity of the current
passing through it to be diminished so as to favor the depositing of drops or
particles and avoid their being carried into the exhaust fan or apparatus. The
separation of the drops or particles from the current of gases and vapors
may be further promoted by constructing the separating chamber of a circular
section horizontally and with the entrance into it directed tangentially so that the
current may have in the chamber a whirling motion the centrifugal action of which
will cause the drops or particles to be thrown against the sides of the chamber.
My apparatus for separating the suspended drops or particles is also advantageously
applicable when the velocity of the current is increased by forcing air into the
furnace instead of or in addition to exhausting the gases and vapors.
In the furnace chamber the bottom is constructed with two or more stages, the
part first receiving the concentrated liquor from the splash chamber being higher
than the remainder. The bottom of each stage may be inclined a little upwards
towards the incinerating end of the furnace; or instead of the furnace being con-
structed with stages or steps the bottom of it may be made with an inclination
downwards towards the incinerating end.
Working doors are provided in the upper parts of the furnace walls or roof,
through which doors workmen can introduce instruments for moving the alkaline
or other substance as it becomes dry towards the incinerating end of the furnace.
I cause the air for combustion in the furnace to be heated by passing through
flues or passages formed in the walls or upon the furnace roof. The air-heating
passage or passages on the furnace roof I prefer to form or enclose by iron plates,
and I thereby utilise heat otherwise lost by radiation, and economise fuel whilst
increasing the heat of the fire gases.
Dated this Fourth day of January 1892.
EDMUND HUNT,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Evaporating and Incinerating Spent
or Used Alkaline Lyes or similar Waste Products.
I, ALFRED SOMMERVILLE CALDWELL, of Greenfield Lodge, Lasswade, in the
County of Mid Lothian, North Britain, Paper Maker, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement, that is
to say :-
My said invention has for its object to effect the evaporation and incineration of
spent or used alkaline lyes or similar waste products in an improved manner, and
more expeditiously than heretofore, so that plant of moderate size is enabled to deal
with larger quantities in an economical manner.
My improved apparatus comprises a furnace chamber in which, or in one part
of which, the incineration takes place, also what is known as a splash chamber in
which the liquor is by paddles or equivalent nechanism, thrown
up into
spray and
also a chamber or space which has in connection with it a fan or other appliance
for rapidly drawing the hot gases through the splash chamber and in contact with
the spray, and to remove the gases and vapors. The alkaline or other liquor after
having, as usual, been more or less heated or concentrated, is run into the splash
chamber; from which the concentrated liquor is transferred to the furnace chamber.
The furnace chamber may be of the ordinary kind but is by preference constructed
with a bottom having two or more stages, the part first receiving the concentrated
liquor from the splash chamber being higher than the remainder. Or instead of
the furnace being constructed with stages or steps the bottom of it may be inclined
down towards the incinerating end.
And in order that my said invention and the manner of performing the same
may be properly understood I hereunto append two sheets of explanatory drawings
to be hereinafter referred to and representing apparatus as made with one modifica-
tion of my improvements.
Figure, 1, on Sheet, 1, of the drawings is a sectional end elevation, Figure, 2,
is a longitudinal vertical section, and Figure, 3, is a sectional plan. Figure, 4, on
Sheet, 2, is a vertical section of a second modification of part of the apparatus.
In these drawings the same reference letters are used to mark the same or like
parts wherever they are repeated.
The structure in which the evaporating and incinerating processes are effected
consists mainly of brickwork, and comprises a splash chamber, A, made with a pan-
like bottom, B, which receives the liquor from a tank, C. The structure also
comprises a furnace constructed with three stages, D, E, F, the highest one, D,
receiving the liquor or semiliquid materials from the splash chamber, A, and these
materials being transferred next to the intermediate stage or space, E, and sub-
sequently to the lowest, F, in which last the complete incineration is effected. At
each side of the lowest furnace space or incinerating hearth, F, and near its outer
end two small fire grates, G, are constructed for burning the necessary fuel, the
fire gases from these grates entering the incinerating space, F, and thence pro-
ceeding along with the gases and vapors evolved by the incineration and evapora-
tion, onwards through the furnace spaces, F, E, D, and the splash chamber, A.
At the outer end of the incineration space, F, a door, H, is provided for raking out
the incinerated materials, the small grates, G+, being placed at the sides to allow
of the discharge door, H, being placed at the end, the operation of drawing out the
materials being more conveniently effected through such end door than through the
side doors hitherto used. In a similar way, instead of doors being provided at
the sides as heretofore for introducing tools with which to work the materials along
towards the incinerating space, F, I provide doors, J, J, at the outer end of each
space D, E, for the introduction of tools with which the workers can operate,

page_text: Air
conveniently through such doors. The difference of level between the stages, D, E, F,
of the furnace is such as to allow workers to stand on the roofs of the lower parts
when operating through the upper doors, J. Each roof is however covered by a
platform of iron plates, K, or of brickwork, L, constructed so as to form air spaces,
through which air passes taking up heat otherwise wastefully radiated.
entering the space formed on the roof of the highest furnace space, D, proceeds
thence by passages, M, arranged at the sides so as not to obstruct access to the
door, J, into the space formed on the roof of the intermediate space, E, and thence
by similar side passages, N, into the space formed on the roof of the incinerating
space, F.
From the last mentioned space the now heated air passes by side
ducts, P, down into the openings between the lateral grates, G.
In the splash chamber, A, there are a number of paddles, Q, on two transverse
shafts driven by means of a sinall steam engine, R, shown in Figure, 3. These
paddles, Q, dipping into the liquor, throw it up in spray, but in order to check the
carrying onwards of the spray by the current of hot gases and vapors, which current
is in my apparatus much stronger than the current in ordinary incinerating apparatus,
I place sheet metal screens, S, S, across the chamber, A. If found desirable there
may be one or more screens placed between the paddles, Q, and the furnace
space, D. And with the view of separating spray as completely as possible from
the gases and vapors I construct a chamber or enlarged space, T, through which
The
the gases and vapors proceed after passing the paddles, Q, and screens, S.
size of the chamber, T, is such that the velocity of the current passing through it
is considerably diminished so as to favor the depositing of the drops or particles
suspended in the gases and vapors. Screens or baffle plates may be fixed in the
chamber, T, to retard the currents passing through.
From the chamber, T, the gases proceed by an outlet at the upper part of it and
remote from the part where they enter the chamber, down a flue, U, to a pair of
fans, V, which propel it into flues, W, leading to a chimney. The engine, R,
already referred to serves for driving the fans, V, for which however a single fan
or any other suitable blower may be substituted. By applying a fan or blower as
herein described I am enabled to very considerably increase the speed with which
evaporation is effected as compared with existing apparatus for the same purpose.
I find in practice that I can employ a current strong enough to show 3 to 4 inches
on the usual water gauge, with a corresponding advantage in rapidity of effect,
without the escaping gases and vapors retaining utilisable heat.
The exhausting action for which the fans, V, or equivalent apparatus are to be
used may be increased to any extent that may be found conveniently or economically
practicable; and any such increase by diminishing the pressure in the chambers or
spaces, A, T, will hasten the evaporating action and thus enable plant of a given
size to deal with larger quantities of lyes. It will however be necessary to avoid
the passage through the furnace spaces, G, F, E, D, of too large a quantity or too
strong a current of air, as the combustion would thereby be rendered too rapid and
a waste of heat would result. The air passing through the furnace spaces may be
limited and regulated by valves in the air inlets; or the opening between the upper
furnace space, D, and the splash chamber, A, may be contracted by bricks or in
any other convenient. way.
.
The separation of the drops or particles from the current of gases and vapors
may be further promoted by constructing the separating chamber (T) of a circular
section horizontally and so that the current may have in the chamber a whirling
motion the centrifugal action of which will cause the drops or particles to be thrown
against the sides of the chamber. Figure, 4, on Sheet, 2, of the drawings is a
vertical section of such a chamber, T, which is represented as having fixed in it
a helix or screw, X, which will cause the current of gases and vapors to gyrate.
whilst passing upwards, the gyration and the contact with the helix both promoting
the depositing of the drops or particles which find their way down to the splash
chamber, A.
If found desirable, comparatively cool liquor from the tank, C, may be directed

page_text: In such case the
fan or fans should be placed at a higher level than as shown, and so that liquor
dripping from them may be drained into the splash chamber, A. It will also be
desirable, when directing liquor upon the fan or fans, either to place the depositing
chamber, T, beyond the fan or fans or to add a second depositing chamber so
that drops or particles carried beyond the fan or fans by the current may be
deposited.
upon the fan or fans, V, to prevent them becoming overheated.
The depositing chamber or chambers (T) may be used with advantage whether
the current through the furnace and splash chamber is produced by an ordinary
chimney of considerable height or by exhausting fans or blowers or by such
apparatus arranged to force air into the furnace, or by a combination of both
forcing and exhausting apparatus.
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. The combination of parts constituting as a whole my improved apparatus for
evaporating and incinerating spent or used alkaline lyes or similar waste products,
substantially as herein before described.
2. The combination with an incinerating hearth or furnace and a splash
chamber, of a depositing chamber and exhaust or forced-draught or exhaust and
forced-draught apparatus, arranged and operating substantially as and for the
purposes herein before described.
3. In combination with evaporating apparatus, an enlarged space or chamber
which by diminishing velocity and with or without whirling motion, promotes
deposition of drops or particles from the current of gases and vapors, substantially
as bereinbefore described.
4. Constructing the furnace parts of evaporating and incinerating apparatus with
two or more stages at different levels, and with end doors for the transference of
the materials from one stage to another and for their final withdrawal, substantially
as hereinbefore described.
5. The construction on the roofs of the furnace parts, of spaces for the passage
and heating of the air supplied to the furnace substantially as hereinbefore
described.
Dated this Tenth day of August 1892.
EDMUND HUNT,
Applicant's Agent.