Improvements in Evaporating Brine and other Solutions, and in Apparatus therefor.
Year: 1896

page_text: Date of Application, 6th July, 1898
Complete Specification Left, 30th Mar., 1897-Accepted, 1st May, 1897
PROVISIONAL SPECIFICATION.
Improvements in Evaporating Brine and other Solutions, and in
Apparatus therefor.
We, EDWARD JAMES DUFF, Engineer, and JOHN BROCK, Chairman, both of The
United Alkali Company Limited, of. G 11 Exchange Buildings, Liverpool, in
the County of Lancaster, do hereby declare the nature of this invention to be as
follows:-
"
Many attempts have been inade to apply the "multiple effect vacuum evaporating
process to the evaporation of solutions, but so far with little success. The difficulty
of removing the salts or solids from vessels under vacuum and the rapidity with which
the numerous heating tubes of such apparatus are rendered inefficient by incrustation
are some of the causes which have contributed to the failure of the system of evaporating
solutions by multiple effect in vacuo.
This invention has for its object the evaporation of solutions in such manner that
the actual process of evaporation and the consequent separation of salts or solids shall
take place in one vessel of simple construction not liable to become inefficient by
incrustation and that the supply of the necessary heat shall take place in another
vessel in which no deposit of salts or solids shall take place and in which a considerable
amount of the heat required for the evaporation shall be recovered from the vapor
given off by the solution itself.
In order that this invention may be clearly understood we will describe the process
and apparatus as applied to the evaporation of brine, though the said apparatus may
be used for the evaporation of any other solutions which are not injured by contact
with air if modified to suit individual circumstances, for example by the addition of
crystallising tanks.
The apparatus constructed according to this invention consists of two tubular heaters
through which the brine passes on its way to the evaporating vessel hereinafter called
the evaporator. The first of these heaters is heated by means of the steam given off
by the brine in the evaporator; the second is heated from a separate source, such
for example as the waste steam of an engine or by live steam. In passing through
these vessels the brine is heated as nearly to its boiling point as is practicable. The
heated brine is then conveyed to the evaporator, which is preferably a vertical
cylindrical vessel of considerable height, through which the brine descends in thin
streams or in the form of spray. This vessel may be provided with baffling plates
horizontal or inclined which may be perforated and so arranged as to retard the flow
of the brine, and to permit the passage in an upward and contrary direction of a current
of hot air.
This current of air, which is forced through the evaporator by means of a fan or
pump, meets the hot brine and takes up as much vapour as the vapour tension and
the temperature of the brine will permit. The heat necessary for the evaporation
is furnished partly by the hot air and partly by the hot brine itself which in descending
through the evaporator becomes cooled. This cooled brine flows into a tank which forms
the bottom of the evaporator where it deposits the salt.
This tank extends outwards from the bottom of the evaporator and is open to the
atmosphere, but is luted off by a seal plate dipping sufficiently deeply into the brine
to prevent the escape of the internal heated air which is under a pressure somewhat
greater than atmospheric pressure. This arrangement permits the continuous

page_text: withdrawal or fishing either by mechanical fishing apparatus or by hand of the salt
which has separated.
The cooled brine from which the salt has been separated flows into another tank or
other tanks and is then pumped (together with as much fresh filtered brine as is
necessary to replace the water evaporated) again through the two heaters and
passes again through the evaporator and thus circulates continuously through the
apparatus.
The air and vapour which leave the top of the evaporator through a suitable pipe are
conveyed to the first heater, which may consist of an ordinary tubular arrangement,
the air and steam given off by the evaporator circulating around the pipes whilst the
brine flows in a contrary direction through the pipes or vice versa. The brine thus takes
up the latent heat of its own vapour and this constitutes a second effect.
We prefer to surround the evaporator with a steam jacket to assist in the evaporation
and in preventing loss of heat.
The condensed water flowing from the several heaters and steam jacket we may
utilize to heat the air necessary for the process, and also for heating the fresh brine,
by causing such condensed water to surround and flow in one direction along a number
of pipes, while the air or the brine flow in an opposite direction through the pipes or
rice versa the air being further heated either by live or exhaust steam or directly
by fuel.
The circulation of the brine through the apparatus is maintained by suitable pumps
and the air is forced through the air heater, the evaporator, and the brine heater, by
means of a blower or pump.
All external surfaces of the apparatus should be protected against loss of heat
by radiation.
Dated th: cih 1
CT
1000
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
Improvements in Evaporating Brine and other Solutions, and in
Apparatus therefor.
We EDWARD JAMES DUFF, Engineer, and JOHN BROCK, Chairman, both of The
United Alkali Company Limited, of G 11 Exchange Buildings, Liverpool, in the
County of Lancaster, 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:---
Many attempts have been made to apply the "multiple effect vacuum evaporating
process" to the evaporation of solutions but so far with little success. The difficulty
of removing the salts, or solids, from vessels under vacuum and the rapidity with
which the numerous heating tubes of such apparatus are rendered inefficient by
incrustation, are causes which have contributed to the failure of the system of
evaporating solutions by multiple effect in vacuo.
This invention has for its object to effect the evaporation of solutions in such
manner that the actual process of evaporation and the consequent separation of salts,
or solids, shall take place in one vessel of simple construction not liable to become
inefficient by incrustation, and that the supply of the necessary heat shall take place,
cr mainly take place, in another vessel in which there shall be no deposit of salts, or
solids, and in which a considerable amount of the heat applied for effecting the
evaporation shall be recovered from the vapour given off from the solution.
In order that this invention may be clearly understood and to simplify the

page_text: description we will describe with reference to the accompanying drawing the process
and apparatus as applied to the evaporation of brine, though the said apparatus may
be used for the evaporation of any other solutions which are not injured by contact
with air the said apparatus being of course modified if necessary to suit individual
circumstances, for example by the addition of crystallising tanks.
Figure 1 is a vertical section and Figure 2 is a plan of apparatus constructed
according to this invention. It consists of two tubular heaters A and B through
which the brine passes on its way to the evaporating vessel C, hereinafter called the
evaporator. The first heater (A) is heated by means of the steam given off by the
brine in the evaporator C; and the second heater (B) is heated by a separate source
of heat, such for example as the waste steam of an engine, or by live steam. In
passing through these heaters A and B, the brine is heated as nearly to its boiling
point as is practicable. The heated brine is then conveyed to the evaporator C,
which is preferably a vertical cylindrical vessel of considerable height, through which
the brine descends in thin streams or in the form of spray. This evaporator C, may
be provided with horizontal or inclined baffling plates which may be perforated, and
50 arranged as. to retard the flow of the brine, and to permit the passage of a current
of hot air in an upward direction contrary to that of the brine.
This current of hot air, which is forced through the evaporator C, by means of a.
fan pump or blower D, meets the hot brine and takes up as much vapour as the
vapour tension, and the temperature of the brine, will permit. The heat necessary
for the evaporation is furnished partly by the hot air and partly by the hot brine
itself which in descending through the evaporator C, becomes cooled. This cooled
brine flows into a tank E which forms the bottom of the evaporator C, where it
deposits the salt. This tank E extends outwards from the bottom of the evaporator C,
as seen in the plan and is open to the atmosphere, but is luted off by a seal plate or
continuation of the evaporator dipping sufficiently deeply into the brine to prevent
the escape of the internal heated air which is under a pressure somewhat greater than
atmospheric pressure. This arrangement permits the continuous withdrawal, or
fishing, either by mechanical fishing apparatus, or by hand, of the salt which has
separated.
The cooled brine from which salt has been separated flows into another tank, or
other tanks, (such a tank is shewn at F) and is then pumped (together with as
much fresh filtered brine as is necessary to replace the water evaporated) by the
pumps at G, again through the two heaters A and B and passes again through the
evaporator C, and thus circulates continuously through the apparatus.
The air and vapour which leave the top of the evaporator C, are conveyed through
a pipe H to the first heater A which may consist of an ordinary tubular arrangement,
the air and steam from the evaporator C, passing around the pipes whilst the brine
flows in a contrary direction through the pipes or vice versa.
The brine thus takes
up the latent heat of the said air and vapour and this constitutes a second effect.
We prefer to surround the evaporator C by a steam jacket to assist in the evapora-
tion and in preventing loss of heat.
The condensed water flowing from the heaters and steam jacket may be utilised to
heat the air necessary for the process, or for heating the fresh brine, or for both
purposes by causing such condensed water to surround and flow in one direction
along a number of pipes while the air or the brine flows or both flow in an opposite
direction through the pipes or vice versa the air being further heated either by live,
or exhaust, steam, or directly by fuel.
It will be evident that the second effect may be dispensed with, in which case the
steam or vapour given off by evaporation in the evaporator C, will escape into the
atmosphere, and only one heater will be necessary.
All external surfaces of the apparatus should be protected against loss of heat by
radiation.
The details of the arrangement and connection of the apparatus may of course be
varied. In the arrangement illustrated the brine is pumped from the well F by the
pumps at G which deliver the said brine through the tubes in the tubular heater A.

page_text: The brine leaves the heater A at the top and passes by the pipe a to the. heater. B. the
top portion of which is divided into two compartments.by. a vertical partition plate.b.
The brine passes downwards through the half of the number, of tubes which open
into one of the said compariments and ascends through, the other half of the, number,
of tubes, when it issues properly heated. into the other of the compartments at the.
top of the heater and passes by the pipe.c into the chamber c at, the top of the
evaporator C the bottom of which chamber constituting the top of the evaporator.C
consists of a perforated plate so that as the brine passes therethrough it is divided.
into spray or fine streams and in its descent through the evaporator C the said brine
meets a current of air which enters through the openings disposed round, the
evaporator C at the lower part thereof the said air being propelled by the blower D
through the pipe d and a tubular heater I into the jacket J surrounding the evaporator C
at the part where the openings.c³ are situated.
. The said air is heated by the condensed water passing by the pipes a³ ³ from the
bottom of the heaters A and B, into the heater I."
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what
we claim is :-
1. In the evaporation of brine or other solutions effecting the heating of the brine
or solution in one vessel, and then exposing it in a divided state to the action of a
current of air in a separate vessel for the purpose of evaporation substantially as
hereinbefore described.
2. In the evaporation of brine or other solutions the utilization of the mixture of
air and steam or vapour, derived from the evaporation of the brine or solution by
means of a current of air, by causing it to heat the incoming brine or solution thus
securing a second effect substantially as hereinbefore described.
3. The general arrangement and combination of parts constituting the apparatus
for evaporating brine or other solutions substantially as herein before described and
illustrated in the accompanying drawings.
Dated this 30th day of March 1897.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.