Improvements in Apparatus for Recovering Soda and other Chemicals from Spent Liquors.
Year: 1890

page_text: Date of Application, 11th Nov., 1890-Accepted, 24th Jan., 1891
COMPLETE SPECIFICATION.
Improvements in Apparatus for Recovering Soda and other Chemicals
from Spent Liquors.
I, LEWIS DESCHURET ARMSTRONG, of 221, West Church Street, Lock Haven,
County of Clinton, State of Pennsylvania, United States of America, Manufacturer,
do hereby declare the nature of my invention for "IMPROVEMENTS IN APPARATUS
FOR RECOVERING SODA AND OTHER CHEMICALS FROM SPENT LIQUORS," and in
what manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
My invention relates to apparatus for reclaiming soda ash and consists of certain
improvements therein which are fully set forth in the following Specification and
shown in the accompanying drawings which form a part thereof.
The object of my invention is to effectively accomplish the evaporation of liquids
from liquors for the purpose of recovering chemicals contained therein, with
particular reference to the recovery of soda ash from the spent liquors of pulp
mills, &c.
More particularly my invention relates to the construction of the evaporating
apparatus, and contemplates the employment of a rotary cylinder through which
the liquor to be treated is caused to flow and to be subjected to the action
of heat.
The object of my improvement is to cause the liquor under treatment while
traversing the rotating cylinder to be subjected to contact with a large heated area,
and with this object I construct my rotary cylinder in such a manner that the liquor
is caused to traverse through a series of shells or concentric cylinders to be brought
in contact with their internal and external surfaces.
My invention also consists in certain improvements in introducing the liquor into
the cylinder and in causing it to flow through the cylinder, and in the devices for
withdrawing the concentrated liquor, and in other constructions and combinations of
parts hereinafter more fully set forth and claimed.
In the drawings:
Fig. 1 is a sectional side elevation of my improved apparatus;
Fig. 2 is a vertical sectional view of the same on the line ww of Fig. 1;
Fig. 3 is a similar view on the line a
;
Fig. 4 is a similar view on the line y y ;
and
Fig. 5 is a sectional side elevation on a reduced scale showing a modification of my
invention.
A is the fire box, the particular construction of which is immaterial to my
invention. I prefer, however, to have it mounted upon wheels a, so that it may be
moved to or from the evaporating cylinder. B is the evaporating cylinder or
drum, within which are arranged a series of concentric cylinders CC, and while
in the drawings I have shown two of these inner cylinders and prefer that number,
it is apparent that the number may be increased or diminished as desired. These
inner cylinders C C are supported within the outer drum or cylinder B by means
of bolts b. The inner cylinders C are so arranged with reference to each other
that they project beyond each other at opposite ends, that is to say, at one end
the cylinder C projects beyond the cylinder C, and at the other end the cylinder C
projects beyond the cylinder C, and the same relative arrangement would be made if
other cylinders were employed. The ends of the cylinders which project beyond the
ends of the cylinder within are closed as shown at c.
I find it advantageous to arrange upon the inner surfaces of the cylinders B, C
and C longitudinal ribs or flanges D, the number of which is unimportant. E is a
liquor supply pipe, preferably constructed in the form of a coil, opening into the end
D
077

page_text: of the internal cylinder C and leading from the fire box A so that the heat from the
fire box in passing to the cylinder B will pass through and about the coil E and heat
the liquor before it is introduced into the rotary cylinder.
In practice I find it expedient to have this supply pipe arranged upon the fire box
as shown, and provided with a funnel F through which the liquor may be introduced.
The internal cylinder (opens to the fire box A, and to prevent the escape of heat
into the atmosphere without passing into the cylinder, I prefer to arrange angle
irons G G¹ on the end of the fire box and cylinder about the opening between them
to prevent the escape of heat. H is the smokestack through which the smoke and
products of combustion from the cylinder B are allowed to pass off, the end of the
cylinder B opening into the smokestack. I is a pan or receptacle arranged imme-
diately below the open end of the cylinder B to receive the liquid from the cylinder or
drum after it has traversed the same. J is a valve outlet from the pan or receptacle I
to a second receptacle K into which the liquor from the receptacle I is allowed to
flow and in which it may be carried to the calcining furnace.
The drum or cylinder B, provided with a series of internal cylinders C C¹, is
supported horizontally between the fire box A and the chimney H, and may be
rotated in any convenient manner, though in practice I prefer to employ the apparatus
illustrated, consisting of the smooth, solid, metal rings L L projecting a slight
distance from the outer surface of the drum or cylinder and resting upon flanged
wheels M M carried by shafts N, which may be driven in any convenient manner.
By this construction the drum or cylinder is more effectively supported and may
be rotated without jarring or lateral displacement.
From the foregoing description of the drawings the operation of my apparatus will
be readily understood. Heat is supplied from the fire box A, and the cylinder or
drum B is rotated in the manner described. The liquor to be treated is introduced
through the funnel F through the coil pipe E into the end of the internal cylinder C³.
This internal end of the cylinder (' is provided with a flange e so that the liquor from the
supply pipe E is prevented from flowing back into the fire box, but is caused to flow
forward through the inner cylinder C, and the rotation of the cylinder or drum B
causes the liquor to spread out over the entire inner surface of that cylinder. Upon
reaching the open end of the internal cylinder the liquor drops upon the inner surface
of the next cylinder, the end of which, as heretofore stated, projects slightly beyond
the end of the cylinder C¹ and has its ends c closed. The liquor flows over the inner
surface of this cylinder and reaching the open end drops upon the inner surface of
the cylinder B and thence flows to the open end of that cylinder and out into the
receptacle 1.
с
The longitudinal ribs or flanges D, arranged upon the inner surfaces of the
cylinders B and C, cause a portion of the liquor as it comes in contact with them to
flow off upon the outer surfaces of the adjacent inner cylinders, and by this means
the area of heating surface over which the liquor passes is greatly increased, the liquor
passing in its transit through the evaporating cylinder over both the inner and the
outer surfaces of the cylinder C' and the inner surface of the outer cylinder B whence
it drops into the receptacle I.
By having the inner cylinder only open to the fire box and closing the end of the
cylinder Cadjacent to the open end of the internal cylinder and forming the opposite
end of the cylinder B closed, as shown, the heat is caused to traverse successively
through the concentric cylinders in the manner indicated by the arrows, being thus
brought in contact with both the inner and outer surfaces of the cylinders C and C
and the inner surface of the outer cylinder or drum B, whereby the liquor traversing
these cylinders in the manner heretofore described is subjected to a greater degree of
heat and contact with heated surfaces and is more thoroughly evaporated or freed of
its liquid portion.
In the modification shown in Fig. 5 one end of the drum or cylinder opens into the
fire box with access for the heat to the interior of all of the shells. The liquor is
introduced into the innermost shell or cylinder C at the opposite end from that adjacent
to the fire box A, and the projecting end of the cylinder in lieu of having the

page_text: closed end c is provided with a small annular flange. This flange prevents the liquor
passing out of the cylinder without traversing the cylinder, and acts for that purpose
in a similar manner with the closed end c, while by forming the end open as described
the products of combustion are all allowed to pass directly through the evaporator.
While I prefer the details of construction which are here shown, I do not limit my
invention to them, as it is apparent that they may be modified in many ways without
departing from the principles of it.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1st. In an apparatus for reclaiming soda ash the combination of a rotary evaporator
consisting of a series of shells or cylinders arranged one within the other, a source of
heat communicating with the interiors of all of said shells, whereby the products of
combustion from said source of heat may pass through each of said shells, and a
supply pipe for supplying the liquor to be treated into the interior of said evaporator,
whereby the products of combustion come directly in contact with the liquor under
treatment.
2nd. The combination of an evaporating cylinder having an opening for the heat
and liquor at one end, a fire box or equivalent heat supplying device, and a liquor
supply pipe carried by said fire box arranged about the outlet of said fire box to the
evaporating cylinder whereby the liquor is superheated before it is introduced into
the evaporating cylinder.
3rd. A rotary evaporator consisting of a series of shells or cylinders arranged one
within the other and each projecting beyond the adjacent inner shell or cylinder at one
end and having a flange about said projecting end to cause the liquor to traverse
successively from one cylinder to another.
4th. The rotary evaporator formed of the series of shells or cylinders arranged one
within the other and provided with longitudinal ribs or flanges on their inner surfaces
adjacent to the outer surface of the adjacent cylinder to cause a portion of the
liquor to flow from said flanged or ribbed inner surface upon the outer surface of
the adjacent inner cylinder.
Dated thi hih da..
ataka A 13 1800
LEWIS D. ARMSTRONG.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.