Improvements in Multiple Effect Evaporating Apparatus.
Year: 1891

page_text: Date of Application, 22nd Jan., 1891
Complete Specification Left, 23rd N.v., 1891-Accepted, 24th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in Multiple Effect Evaporating Apparatus.
I, ALFRED CHAPMAN of 17 York Street, Liverpool, Civil Engineer, do hereby.
declare the nature of this invention to be as follows:-
--
My invention has reference to multiple effect evaporating apparatus of the kind
known as the "Yaryan "the general construction and operation of which are
Various modifications of and
described in Specification No. 14162 of 1886.
improvements upon the Yaryan apparatus are also described in Specifications
Nos. 213 of 1888, 11485 of 1888, 17809 of 1888 and 18383 of 1888.
In the employment of this apparatus for the evaporation of some solutions and
more particularly those containing soda ash which are blown off from esparto and
straw boilers in paper works it has been found that unless the apparatus be washed
out, once or twice a day the tubes become so foul as to seriously injure or decrease
their efficiency. This drawback is to a great extent due to the long worms or
tubes through which the liquor to be heated has to pass.
It has also been found in practice that with the Yaryan apparatus it is impossible
to practically concentrate these liquors with advantage to more than 40° or 42º
Twaddel at the temperature of the liquor leaving the last pan of the series corre-
sponding to the boiling point of the liquor under an absolute pressure of 4 or 5 inches
of mercury without inconveniently fouling the tubes.
Now the object of my invention is to increase the efficiency of multiple effect
apparatus of the kind referred to first by dispensing with the necessity of washing
out once or twice a day which involves a loss of 2 or 4 hours working without
corresponding decrease in fuel consumption and the use of a larger apparatus than
would be necessary if worked continuously; and secondly by enabling the apparatus
to discharge the concentrated liquor at from 50° to 60° Twaddel at which density
it is in a much better condition to be received by the incinerating furnace or
roaster which will complete the treatment with much less coal than if supplied with
liquor at 40° to 48°.
For the purpose of my invention I combine with the Yaryan apparatus one or
more evaporating vessels with vertical heating tubes and by preference with
vertical heating tubes through which the liquor to be heated passes upwards
from below and from which it runs off as soon as it has arrived at the top. I
arrange the additional evaporating vessel or vessels to receive the vapor from the
last vessel of the Yaryan apparatus in the usual manner but I conduct the con-
densations from the last vessel of the Yaryan apparatus to the drum or steam spacė
of the additional vessel or of the first additional vessels if more than one by an
inverted syphon and I conduct the liquor from the last vessel of the Yaryan
apparatus to the bottom of the additional vessel or of the first additional vessels
if more than one by an inverted syphon. The vapor from the liquor heated in the
additional evaporating vessel or in the last additional vessel if more than one will
go to the condenser in the usual way and, the concentrated liquor from the said
vessel will be extracted. by a pump actuated either by its own special motor or by
the vacuum engine or in any other convenient way.
The addition to an apparatus of the Yaryan type of one or more vertical
evaporating vessels constructed preferably and working as above described will
allow of the liquors being concentrated to from 50° to 60° Twaddel as may be
desired instead of to 40° as in an ordinary Yaryan apparatus and will also prevent
fouling or incrustation of the heating tubes as well as increase the economy with

page_text: which the evaporation is carried on, because by adding one or more vessels the
number of "effects is correspondingly increased.
Dated this 22nd day of January 1891.
J. C MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Multiple Effect Evaporating Apparatus.
I, ALFRED CHAPMAN of 17 York Street, Liverpool, Civil Engineer, do hereby
declare the nature of this invention and in what manner the same is to be
perfornied, to be particularly described and ascertained in and by the following
statement :-
My invention has reference to multiple effect evaporating apparatus of the kind
known as the " Yaryan" the general construction and operation of which are
described in Specification No. 14162 of 1886. Various modifications of and
improvements upon the Yaryan apparatus are also described in Specification
No. 213 of 1888, 11485 of 1888, 1-7809 of 1888 and 18383 of 1888.
In the employment of these apparatus for the evaporation of some solutions and
more particularly those containing soda ash which are blown off from esparto and
straw boilers in paper works it has been found that unless the apparatus be washed
out once or twice a day the tubes become so foul as to seriously injure or decrease
their efficiency. This drawback is to a great extent due to the long worms or
tubes through which the liquor to be heated has to pass.
It has also been found in practice that with the Yaryan apparatus it is often
impossible to practically concentrate these liquors with advantage to more than 40°
or 42° Twaddel at the temperature of the liquor leaving the last pan of the series
corresponding to the boiling point of the liquor under an absolute pressure of 4
or 5 inches of mercury without inconveniently fouling the tubes.
Now the object of my invention is to increase the efficiency of multiple effect
apparatus of the kind referred to, first by dispensing with the necessity of washing
out once or twice a day which involves a loss of 2 or 4 hours working without
corresponding decrease in fuel consumption and the use of a larger apparatus than
would be necessary if worked continuously, and secondly by enabling the apparatus
to discharge the concentrated liquor at from 50° to 600 Twaddel, at which density
it is in a much better condition to be received by the incinerating furnace or roaster,
which will complete the treatment with much less coal than if supplied with liquor
at 40° to 42º.
For the purpose of my invention I combine with the Yaryan apparatus one
or more evaporating vessels with vertical heating tubes and by preference with
vertical heating tubes substantially as described in my Specification No. 1752
of 1888 through which the liquor to be heated passes upwards from below and
from which it runs off as soon as it has arrived at the top. I arrange the additional
evaporating vessel or vessels to receive the vapor from the last vessel of the Yaryan
apparatus in the usual manner, but I conduct the condensations from the last
vessel of the Yaryan apparatus to the drum or steam space of the additional
vessel or of the first additional vessels if more than one by an inverted syphon
in the manner explained in my Specification No. 2511 of 1888, and I conduct the
liquor from the last vessel of the Yaryan apparatus to the bottom of the additional
vessel, or of the first additional vessels if more than one by an inverted syphon
in the manner also explained in the said Specification. The vapor from the liquor
heated in the additional evaporating vessel, or in the last additional vessel if more
than one, will go to the condenser in the usual way, and the concentrated liquor
from the said vessel will be extracted by a pump actuated either by its own special
motor or by the vacuum engine or in any other convenient way.

page_text: The addition to an apparatus of the Yaryan type of one or more vertical
evaporating vessels, constructed preferably and working as above described, will
allow of the liquors being concentrated to from 50° to 60° Twaddel as may be
desired instead of to 40° as in an ordinary Yaryan apparatus, and will also prevent
fouling and incrustation of the heating tubes, as well as increase the economy with
which the evaporation is carried on, because by adding one or more vessels the
number of "effects" is correspondingly increased.
The accompanying diagrammatic view will serve to illustrate my invention.
a be indicate three vessels forming a triple effect evaporating apparatus of the
Yaryan type. d is an additional vessel which in accordance with my invention I
combine with the vessels of the Yaryan triple effect. This additional vessel is one
having vertical tubes passing through the steam drum, the liquor entering the
lower part of the vessel and passing upwards through the tubes from which it runs
off as soon as it has reached the top. e is a pipe taking the vapor from the last
vessel c of the Yaryan apparatus in the usual manner, into the heating drum of the
vessel d. is an inverted syphon which conducts the condensations from the vessel c
to the drum of the vessel d'and g is an inverted syphon which conducts the partially
concentrated liquor from the vessel e to the lower part of the vessel d. is a pipe
through which the vapor from the vessel goes to the condenser i with which is
connected the air pump k. The concentrated liquor after passing up through the
vertical pipes in the steam drum of the vessel d, flow off by the pipe to the
extracting pump m.
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 1
claim is :-
:-
גי
1. In a multiple effect evaporating apparatus the combination with an apparatus
of the "Yaryan type, of one or more vertical evaporating vessels the first of
which receives the vapor, the condensations and the partially concentrated liquor
from the last vessel of the Yaryan apparatus substantially as and for the purpose
hereinbefore described.
2. Constructing multiple effect evaporating apparatus substantially as herein-
before described and illustrated in the accompanying diagrammatic view.
Dated this 19th day of November 1891.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.