provements in the Softening of Water and in Apparatus therefor.
Year: 1890

page_text: Date of Application, 7th May, 1890.
Complete Specification Left, 9th Mar., 1891-Accepted, 7th May, 1891
PROVISIONAL SPECIFICATION
Improvements in the Softening of Water and in Apparatus therefor.
I WILLIAM LAWRENCE of 5 Richmond Gardens, Shepherd's Bush in the
County of Middlesex, Engineer do hereby declare the nature of this invention to
be as follows:-
The main feature of this invention consists in taking advantage of and in utilizing
the carbonic acid gas naturally existing in all water so as to throw out of solution
the salts of lime and magnesia, the water being treated with alkali then heated, and
filtered from the resulting deposit.
I have observed that when a natural water is treated with an alkaline solution of
for instance caustic soda and heated to the boiling point no evolution of gas in the
form of carbonic acid gas takes place, whereas the same water heated without the
admixture of the soda solution throws off carbonic acid gas very readily and sets up
a bubbling action long before the boiling point is reached.
I have also observed that hard water containing organic or slimy matter, that
will coagulate on boiling, is by the addition of soda freed from such impurities when
heated to the boiling point and precipitated and filtered, the impurities precipitating
with the carbonates of lime and magnesia.
At the same time I should also observe that the composition of waters and the
impurities they contain vary so much that one universal treatment does not suffice
for all. Sometimes it becomes necessary to mix other or known ingredients with
the soda solution according to the nature of the water as determined by analysis or
otherwise and then by heating precipitation or filtration to remove such impurities
as will coagulate or separate together with the salts of lime at one process.
I should also remark that the removal of the hardness and impurities from water
by boiling has this advantage over treatment in the cold inasmuch as at the boiling
temperature micro-organisms are in the general way destroyed.
As is well known carbonic acid gas, the principal gas contained in water, holds
in solution the carbonates of lime and magnesia, now when lime water is added to
such a water in sufficient quantity to neutralize the free carlonic acid, these
carbonates hitherto held in solution by this carbonic acid become precipitated and
the water is found to be approximately softened, but the other salts of the earthy
metals, such as the sulphates nitrates and chlorides undergo no change by this
process.
Again, the addition of caustic lime or hydrate of lime can never be accurately
performed with a water of varying hardness or where the supply is affected by
rainfall or other variable causes, yet if an insufficiency or an excess of caustic lime be
added, carlonate of line will in the cre case be held in solution or free lime in the
other.
From this it is obvious that no process of adding pure lime to water can suffice to
remove all the salts of lime.
Several processes are in vogue in which caustic lime and soda are employed with
water in the cold in order to precipitate the line alts and to remove the sulphates,
but the necessary chemical interchange is very difficult in the cold and a considerable
time and a great excess of seda tre mecessary in order to partially remove the lime
salts by deposition or filtration. Practically up to the present time no process is in
vogue that will give soft water perfectly free frem salts of lime and magnesia.
And the reason is obvious when we leerme cognizant of the following facts, riz.
that the quantity of suda necessary to reduce the lime salts in water increases as
the temperature decreases; and that the length of time required in the cold is very
considerable whereas in the heat, the time required is but momentary. The excess of

page_text: carbonic acid exists also in the cold but not at the boiling point of water. There
fore water treated in the cold must have an alkali added in the form of lime or soda
or such like to remove this excess of carbonic acid.
Now my process differs from others by causing the final chemical interchanges to
take place at or near the boiling point and in permitting the loss only of carbonic
acid or dispelling it when it remains or escapes after transforming with the soda the
salts of lime and magnesia into carbonates and in leaving no free carbonic acid to
solution.
hold such carthy salts in
In this way treat a water containing the greatest degree of hardness and trans-
form it into a water possessing not a single degree of hardness, using at the same
time just a sufficient quantity of caustic soda or alkaline salts to form the equivalents
of all the lime and earthy salts except the carbonates with a very slight addition,
as a margin to compensate for any irregularity or variation in the hardness of the
water or the strength of the alkaline solution.
Then by henting such treated water with waste gases from the furnace or with
waste or exhaust steam and by interchanging the heat when the water is required
|
all the
to be used in the cooled state and by depositing and filtering separate
obnoxious sedimenting matters from the water prior to its use for evaporative
purposes and in this way prevent incrustation, deposit or scum in boilers and tend
to prevent "priming" and obviate the objections which, hard, impure non deposited
unfiltered water pussesses for dyeing, laundry, and general
purposes,
In carrying my process into effect. I require to employ apparatus so modified as
to suit the purposes for which it is required whether it be for softening water for
the use of steam boilers for dye works, laundries or water works or for household
general purposes.
and
the
It has been considered impracticable to trent water in the heat in consequence of
difficulty and expense and cost of fuel. This difliculty is by my apparatus
overcome but it remains for me to explain for each of the several purposes, the
manner in which it is performed and the apparatus for accomplishing it.
To save expense in fuel employ waste heat in a variety of forms, either as
waste hent from the furnace or from the products of combustion, or waste or exhaust
steam or by interchanging the beat from the boiled water to the water to be boiled
or by boiling the water in a separate vessel or apart from the heating surfaces of
the steam boiler by using steam direct from the boiler or by heating and partially
cooling the water when it is required for use in the partially cooled or tepid state
or when the heat at command is insufficient for the delivery of water in the boiling
state.
In carrying out the process for the various uses mix with water the relatively
required quantity of soda or alkaline solution or material either in solution or other
wise, and pass the same through a heating apparatus and a depositing or filtering
apparatus. When the water is required to be used in the cold or partly cold state |
employ a heat interchanging apparatus.
The apparatus may be composed of such in separate parts or two or more of the
parts may be combined in one apparatus.
When the measurer is employed separately it may be for convenience constructed
of a larger and smaller cylinder the one being inside the other, the outer cylinder
being sufficiently strong to withstand the necessary water pressure and fitted with
top and bottom removable covers if necessary according to circumstances. The
inner chamber or cylinder is to contain the caustic soda or alkali and the outer to
contain and mix up the treated water.
A regulated quantity of water is made to
pass into the vessel containing the alkali thereby displacing so much of the solution
in proportion to the water passed into the outside cylinder and not into the vessel
containing the soda; thus a saturated solution of caustic soda would flow from the
inner to the outer chamber in proportion to the main body of the water and the
definite amount of soda per gallon added to it automatically.
The measurer may also be in duplicate, the one part containing a saturated or a
strong solution and the other a weak solution both parts being provided with

page_text: regulating outflow to the inner and outer chamber so as to relatively and respectively
admit the water to each. The two parts can also be set to represent in the one an
excess of soda in the outflow and the other an insufficiency and the two can again
be regulated so as to give the correct proportions that are established by testing.
The measurer may also consist of more than two parts in duplicate and any desired
number of combined chambers may be employed. The parts or chambers may be
arranged concentrically the one inside the other and fixed to a general top and
bottom and fitted with regulating connections between each chamber and the water
supply so that each succeeding chamber may have more water added and so contain
a weaker and a weaker alkaline solution and give the means of adjusting to a nicety
or as correctly as practicable, the exact number of grains added per gallon as a
continuous quantity.
The measurer may also be provided with sight holes and glass tubes or vessels
to give the means of observing the colour, density and general conditions of the
solution. Also test cocks and other necessary attachments may be provided.
The measurer may also contain a water meter to register the number of gallons
passed through and so indicate the time for recharging with the solution according
to the size of the chamber and quantity of solution added on charging.
The heating apparatus mnay, in the case of isolated steam boilers be contained in
In such case a con-
a vessel containing the filtering and depositing chambers.
venient arrangement may be a cylindrical high pressure vessel placed vertically
say 6 ft. more or less in height and of a diameter suited to the capacity of the
boiler.
The top removable cover may be domed and about 1 foot in height, the bottom
removable cover and depositing chamber occupying together about 2 feet and there
would be 4 feet remaining for the depth of the filtering chamber which may consist
of an annular space formed by or between the filtering medium of cloth and the
circumference and shut off from the top and bottom chamber by a projecting ring
at top and bottom of the cylinder proper or the 4 ft. cylinder.
The filtering medium may be placed between an inner and outer perforated
cylinder the outer cylinder being say two inches less in diameter than the cylinder
or pressure vessel leaving an annular space of one inch, for the chamber for the
filtered water.
The fibre filter may be placed in the vertical cylinder and formed of fibrous
substance such as hemp attached to a network or coarse canvas or wire work frame
the hemp being tied or worked into the frame with the fibre outside so as to allow
the water to pass freely through the frame and the sedimentary or filtrable matter
strained back by the fibre which fibre would fall close and form a kind of nap and
yet allow the water to pass freely through the frame and not become blocked as an
ordinary filter cloth would do. The fibre may also project inside and out and the
filter may be freed from sediment or deposit by blowing in steam or forcing in water
in the opposite direction occasionally.
The fibre worked into the network may also be rolled up being attached to metal
rods at top and bottom bent in coils. The top coil could be supported by the top
removable cover and depend from hooks and the bottom coil could be in connection
with a stirrer the shaft of which would pass through the centre of the bottom cover.
In this way the sediment could be dislodged daily. The heating apparatus may be
formed by jacketting the removable dome or otherwise heating the top of the water,
or free steam may be blown in at the pressure of the boiler and made to meet the
water falling in a divided state so as to boil it instantaneously.
A cone shaped directing plate could then direct the sedimentary matters to the
centre of the cylinder s that it may be made to fall or drop a deposit into the
depositing chamber leaving the filter as little work as possible to do. The necessary
fittings and pit cocks, blow off cocks &c. could also be attached and the delivery
pipe would be set to rise at a proper level to maintain the correct water level in the
apparatus.

page_text: For locomotives and where space is an object the whole apparatus must be
condensed so as to reduce the size of the chambers to the smallest dimensions.
For such cases fibre filters may be used or chambers containing fibrous substances
through which the water may traverse and constructed to move in position and
drop the sedimentary matters away when not in use or there may be in this case
also a mechanical arrangement to remove the sediment.
The heat interchanger for large purposes may contain the heating apparatus and
be conveniently formed by placing in a box or vessel say of wood, a sheet or sheets
of metal (say of tinned steel copper or galvanized irony in such a manner as to
divide the box or back into two parts, the one part being for the upward flow of the
water and the other for the downward flow, the plates being either plain or ribbed
to prevent buckling.
The water previously treated in the cold would enter at once near the bottom and
would become heated in ascending to the top where it would become boiled and
then descending on the opposite side of the plates would become cooled in imparting
its heat to the succeeding ascending column, The water in ascending having
attained to very near the boiling point would require but a few degrees of heat
added to cause actual ebullition, the water line being preserved at a few inches
above the top of the plates. Any steam forming may be comlensed in a condensing
box open at the top but formed to dip below the surface of the water or to where it
is below the boiling point on the reverse side to the heating apparatus. The heat
interchanging apparatus would thus combine a heating apparatus placed a few
inches below the water level on the upward flow through which apparatus steam
may be made to pass or to blow through any perforated arms the apparatus may
contain. It would also combine an open condensing box which would be provided
with a condensed water pipe to run off the condensed water downwards and out
through the side of the box. It would also contain the heat interchanging or
conducting plates placed in the wood vessel or back. Now if the vessel be say
9 feet high abom 3 . in breadth and 2 ft. 6 in, in depth the conducting plates may
be placed depthways and vertically on the vessel. If the plates occupied 2 fort of
the depth there would be 6 inches remaining of the depth and if the plates were
8 feet high there would remain 1 foot on the top for water and vapour space
the vessel being provided with a loose lit. Now if the plates were connected in
pairs with strips of rolled metal having chases rolled or formed in them to receive
the edges of the plates they would forin U shaped plates two feet deep.
If again
these U shaped plates were attached together at their other ends either by wood
strips or by strips of metal they would form a continuous plate bent backwards and
forwards the depth of the bends being 2 foot. Thus if the end plates were secured
to the end sides of the vessel and the joints at the bottom made good with wood
packing and a suitable substance to form a joint the back or vessel would thus be
divided into two parts vertically. The depth of the vessel being 2 ft. 6 in. there
would remain 3 inches on the ascending side and 3 inches on the descending as a
general supply space to supply the Ushaped spaces on both the ascending and
descending side. Thus the back would be divided by the U shaped plates into
Ushaped water spaces or chambers the sides of which would heat and cool the
ascending and descending columns of water respectively. Thus the water on rising
and becoming heated would part with its excess of carbonic acid and the salts of
lime and magnesia would become carbonates by the time the boiling point had been
reached and the excess of carbonic acid being driven off in the heat those salts of
lime and magnesia would precipitate and fall to the bottom on both the ascending
and descending sides. If the width of the U shaped spaces were two inches the box
would contain about 300 sq. ft. and if only one inch, double that quantity. The
upward and downward How of the water being gentle would allow of the deposition
of the sedimentary matters to take place.
A modifiention of the heat interchanger may be a number of pipes fixed upright
or placed vertically in a vessel having a double bottom the upper being perforated

page_text: to receive the pipes. The water may be made to enter above the double bottom
and rising upwards and surrounding the pipes, and rise above them and become
boiled and descend inside the pipes and pass away into the chamber formed between
the one bottom and the other. The necessary removable doors for cleaning and
such like are intended to be provided as well as any necessary fittings. The sides
or back and front of the vessel may also be made in part or entirely removable.
The tubes may be round, oblong or other shaped.
For house or domestic purposes the boiler of the kitchen range may have added
to it or contained in it a plate or plates and be converted into a heat-interchanger
by limiting the water spaces that lie against the heating surfaces by placing such
plate or plates about an inch away or distaut from the heating surfaces and so
partitioning off a thin layer of water, which would become heated vertically and
rise on boiling and cause a circulation of the water. Another set of folded Ushaped
plates bent backwards and forwards and placed so as to divide the main body of the
boiler into two parts and extending from above the water line to near the bottom
would divide the boiled water from the unboiled, and on cirenlation the boiled water
would become cooled. The draw off pipe being placed low down on the boiled
water side, the water drawn or passing out of the boiler will have been raised to
the boiling point and softener notwithstanding it may pass out in the cooled state.
For house and small purposes where no special or kitchen boiler is made use of,
the heat from a lamp or gas jet may be made use of. A convenient apparatus for
such purpose may be a vessel having an inverted cone shaped vessel the underside
to act as the lamp reflector and chimney as well as forming the heating surface.
The stand or stem may be a tube containing an inner tube to form the upward
flow, the downward flow being the annular space between the two tubes. Thus
water would pass upwards into the receiving or heating vessel which may contain a
filter and pass into one division of the chamber and pass ont from the other division,
having passed through the filtering medium and become cooled on descending.
Regulating taps and fittings would also be intended and the mixer or measurer may
either be separate or combined in the apparatus.
When the heating apparatus is apart from the heat interchanger and is intended
to utilize the waste gases from the furnace, a convenient form is built up of a stack
of trays or troughs having undulated or folding or U shaped bottoms and corrugated
lids. The U shaped spaces forming the passage for the waste gases which may be
made to pass through or under the trays from end to end or backwards and forwards
being directed by directing plates and chambers at the ends of the trays.
The water could then drop from tray to tray and become boiled and deposited,
the filtering and depositing chamber being also apart.
Another form of heater to utilize waste gases from a chimney is an annular vessel
the centre tube of which forms part of the chimney.
Depositing trays may also be attached to the heat interchanger the trays being
placed on a back the water level of which would be practically the same as that of
the interchanger. These trays may be metal sheets placed an inch or so one above
the other so that the precipitate in the water in traversing the back may become
leposited on the sheets the deposit having to fall or drop only an inch or so.
Dated this 7th day of May 1890.
HERBERT & Co.,
Agents to Applicant.
COMPLETE SPECIFICATION.
> Improvements in the Softening of Water and in Apparatus therefor.
I WILLIAM LAWRENCE of 5 Richmond Gardens, Shepherd's Bush in the
County of Middlesex, Engineer do hereby declare the nature of this invention
and in what manner the saine is to be performed to be particularly described and
ascertained in and by the following statement :—
The object of this invention is to provide a method or process and apparatus for

page_text: softening or purifying water by means of which water of any degree of hardness
may be softened or purified either so that all the hardness femporary as well as
permanent is removed or so that a resultant water of any desired degree of
hardness is obtained, the process being performed in a rapid and continuous manner
so that the treated and softened water is delivered at a uniform rate with less
expenditure of chemicals for a given result than in other processes and consequently
with results of greater purity and with machinery of smaller size and cost.
A main feature of the invention consists in taking advantage of and utilizing the
carbonic acid gus naturally existing in all water for assistance in throwing out the
salts of lime and magnesia, firstly by a process of virtual separation by which
the carbonates of lime or magnesin held in solution by reason of the presence of the
carbonic acid gas are separated and secondly by again utilizing the carbonic acid
gas with caustic alkali such as hydrate of soda to decompose the sulphates, nitrates,
chlorides, and other soluble salts of lime or magnesin whereby these salts are
converted into carbonates and thus separated, the excess of carbonic acid gas being
driven off at the end of the process, that is to say after all, or so much of the lime
and magnesia as is to be removed, is separated in the form of carbonate.
The above process will be carried out or varied in minor particulars according
to first the nature of the water treated as regards its contents, secondly according
to the nature of the resultant water required which will depend upon the purpose
for which it is to be used and thirdly according to the manner in which the process
is conducted.
As is well known corbonic acid gas, the principal gas contained in natural water
holds in solution the carbonates of lime and magnesia. Now when line water is
added to such a water in sufficient quantity to neutralize the free carbonic acid,
these carbonates hitherto held in solution by this carbonic acid become precipitated
and the water is found to be apparently softened. But the other salts of the
earthy metals such as the sulphates, nitrates and chlorides, undergo no change by
this process. Again, the addition of lime enn never be accurately performed with a
water of varying hardness or where the supply is affected by rainfall or other
variable causes, yet if an insufliciency or an excess of lime be added, carbonate of
lime will on the one hand be held in solution, or free lime on the other.
From this it is obvious that no process of adding pure lime to water can suffice
in practice to remove all the salts of lime.
Several processes are in vogue in which lime and soda are employed with water
in the cold in order to precipitate the lime salts and to remove the sulphates. But
the necessary chemical interchange is very difficult in the cold and a considerable
time and a great excess of soda are necessary in order to partially remove the lime
salts by deposition or filtration. Practically, up to the present time no process is in
vogue that will give soft non-alkaline water perfectly free from salts of lime and
magnesia. And the reason is obvious when we become cognizant of the following
facts, that the quantity of soda necessary to reduce the lime salts in water increases
as the temperature decreases, also that the length of time required in the cold is
very considerable whereas in the heat, the time required is but momentary. The
excess of carbonic acid exists also in the cold-but not at the boiling temperature.
Therefore water treated in the cold must have an alkali added in the form of lime
or soda or such like to remove this excess of carbonic acid.
Now my process differs from others by causing the final chemical interchanges to
take place at or near the boiling point aml in permitting the loss only of carbonic
acid or dispelling it when it remains in excess after transforming with the soda the
salts of lime and magnesia into carbonates and so leaving no free carbonic acid to
hold such earthy salts in solution. In this way I treat a water containing the greatest
degree of hardness and transform it into a water possessing not a single degree of
hardness, using at the same time just a sufficient quantity of caustic soda or alkaline
salts to form the equivalents of all the lime and earthy salts except the carbonates
with a very slight addition as a margin to compensate for any irregularity or
variation in the hardness of the water or the strength of the alkaline solution. Then

page_text: | by heating such treated water with waste gases from the furnace or with waste or
exhaust steam and by interchanging the heat when the water is required to be used
in the cooled state and by depositing and filtering I separate all the obnoxious
sedimentary matters from the water prior to its use for evaporative or other purposes
and in this way prevent incrustation deposit or seun in boilers and tend to prevent
priming" and obviate the objections which hard, impure non deposited, unfiltered
water possesses for dyeing laundry and general purposes.
I have observed that hard water containing organic or slimy matter that will
coagulate on boiling is by the addition of soda freed from such impurities when
heated to the boiling point and precipitated and filtered, the impurities precipitating
with the carbonates of lime and magnesia.
At the same time I should also observe that the composition of waters and
the nature of the impurities they contain vary so much that one universal
system of treatment does not suffice for all. Sometimes it becomes necessary to
use other or known ingredients as well as the soda solution according to the nature
of the water as determined by analysis or otherwise and then, by heating, precipita-
tion or filtration to remove such impurities as will coagulate or separate, together
with the salts of lime at one process. I should also remark that the removal of
the hardness and impurities from water by boiling has this advantage, over treat-
ment in the cold inasmuch as at the boiling temperature vital organisms are in the
general way destroyed.
As aforesaid lime maguesia etc. are not soluble in water in the form of carbonates
unless carbonic acid gas is present; the bicarbonates are however soluble.
As, by my process, the carbonic acid gas is driven off by heat the quantity of
hydrate of lime necessary to reduce the bicarbonates is very much lessened; its
action in the heat as well as that of the soda becomes violent and almost instan-
taneous, and the precipitated matter collects in such a form by aggregation of its
particles as to be very easy of filtration or separation, while the returning or
re-utilizing of the carbonic acid gas at the end of the process carbonates any lime
or soda remaining in the caustic form as well as the lime, magnesia ete. resulting
from the chemical interchange induced by the action of the soda upon their
sulphates, nitrates and chlorides. With a temperature of say 50° Fahrenheit
below the boiling point a very fine result may be obtained by the complex actions
going on of driving off carbonic acid by heat while the hydrate of lime is acting
on the bicarbonates and being itself carbonated by the escaping gas.
This method takes advantage of the escaping carbonic acid gas. However by
treating water at the boiling temperature and using carbonate of soda in the place
of caustic soda and no hydrate of lime, the returning of the carbonic acid gas may
be dispensed with in the general way.
The form of the apparatus and the manner of using it, also the kind of chemical
reagent employed and the temperature at which it should be added must be
determined by the general considerations. If a sufficiency of heat at a high
temperature is at command and the water he heated to the boiling temperature
then soda alone will be sufficient, the time of adding the soda being determined by
the nature of the water, its hardness, its purity and the extent to which carbonic
acid gas is present. When free ammonia and albumenoid ammonia are present, the
coagulating point should be reached before addition of the soda for the reason that
in the presence of such alkalies the coagulation would be interfered with.
Again the temporary hardness is removed in proportion to the temperature to
which the water is raised before the addition of the chemical reagent. When the
hardness consists principally of carbonates or bicarbonates and the quantity of
sulphates is very small then the grains of soda per gallon necessary to be added are
few and a sufficiency of carbonic acid is generally to be found in the bicarbonates
to carbonate the few grains of soda added in the caustic form. In such case the
free carbonic acid may be driven off first and allowed to escape and the boiling may
be done in a separate vessel. When on the other hand, the sulphates, nitrates and
chlorides of the earthy metals are abundant, then the carbonic acid must be caught

page_text: and returned when using caustic sodn or else there may not be sufficient carbonic
acid to carbonate the lime te. resulting from the chemical interchange. But this
again depends upon the extent to which the hardness has been removed in the
treatment for removing the temporary hardness and whether the boiling temperature
is that at which the operation is to be conducted. The water of rivers such as the
Lower Thame for instance being highly charged with organic matter may be dealt
with at such temperatures as about 160 Fahrenheit by the use of hydrate of lime
added in the heat. Here it becomes necessary to catch the carbonic acid gas and
to use soda only in small quantities also in the heat. Again the kind of metal used
in the apparatus must be determined by the nature of the water and the purpose
for which it to be used. If iron is advantageous in the purifying of the water
then iron surfaces may be used in the heat interchanger; if the salts of zine will
assist by aiding the coagulation of impurities, then galvanized iron may be used,
but for laundry or washing purposes such metai should be avoided and copper
substituted. When the waste heat at disposal is steam at the ordinary atmospheric
pressure and the use of it as open or free steam objectionable it is difficult to boil
water with certainty. In such ease it is convenient to carry on the process below
the boiling temperature using caustic sod: if sufficiently high temperature can he
reached and the use of hydrate of line not required. If the amount of carbonic
acid present be insufficient to earl te the line and magnesin then carbonate or
bicarbonate of seda must be added in addition to caustic soda to provide for the
insufficiency of carbonic acid.
Having described the principle of the process by which the lime and magnesia
salts are derived in the form of carbonates my invention further consists in the
method of applying heat for operating the process, also in the method of mixing
chemicals, in providing for the speration of the carbonates in a convenient manner
and prevention of incrustion for the filtration of the water and for the freeing of
the filters.
In carrying my process into effect 1 require to employ apparatus so modified as
to suit the nature of the water to be softened or purified and the purposes for
which it is required whether it be for the use of steam boilers, for dye works,
laundries or water works or for household and general purposes.
It has hitherto been considered impracticable to treat water in the heat in con-
sequence of the difficulty and expense and cost of fuel.
To save expense in fuel I employ a heater in which waste heat is used in one or
more of a variety of forms either as waste heat from the furnace or from the
products of combustion or waste or exhaust steam or by interchanging the heat
from the heated water to the water to be heated or by heating the water in a
separate vessel or apart from the heating surfaces of the steam boiler by using
steam direct from the boiler or by heating and partially cooling the water when it
is required for use in the partially cooled or tepid state or when the heat at
command is insuflicient for the delivery of water in the heated state. It is however
usually most convenient to employ waste steam for heating the water and when the
water is to be delivered in a cooler state than that to which it has been heated in
the course of the process it is preferable to employ the interchange of heat from
the heated water to the cold water adding the additional hent necessary for loss etc.
by the method of further heating the water by waste steam after it has been heated
as far as possible by the previously heated water.
The method of heating consists in providing or causing the water to arrive in a
location for heating in a body, so that the heat is applied at or to the upper part
or level of said ly or so that heat is applied at different points or all along the
height of the body of water but at each point but slightly in excess of the
temperature of the water at that point or level, the uppermost level being thereby
made the hottest and the lowermost level retaining the initial low temperature of
the water which is caused to rise by continually drawing off heated water at the
top and supplying unheated water at the bottom, this whole process being performed
in a chamber or receptacle having preferably no ledges or interruptions of any

page_text: kind but only vertical walls or walls sloping at such a steep angle that the seaument
thrown out of solution by the action of the process will fall freely to the bottom
and will thus pass through colder and colder layers until eventually arriving on the
bottom it remains thus in the coldest layer.
It is known that when no hydrate of soda or other chemical is used for removing
the "permanent" hardness and the "temporary" hardness alone is removed or
when the supply of chemical ceases from any cause the tendency of the salts thrown
out of solution is often to form a hard incrustation.
By use of the above method of heating, incrustation of the apparatus is avoided
by causing the deposited matter to fall into colder substrata of water and to remain
in such cold substratum, this being effected as aforesaid by causing the water to be
treated to rise in a column in a chamber where heat is applied to it at the top and
also in certain instances to the sides by a peculiar method hereinafter described and
termed heat interchange, and, where the water is cooled again by cooling said
water gradually in a descending column whereby the temperature of the body of
water under treatment at any level is proportional to the height of such level the
lowest level being the coldest and the highest level the hottest both on the ascending
and descending sides.
If the water is required to be hot it is drawn off at the top after the above
treatment, if it is required to be cooled then the heat contained in it may be trans-
ferred to the water to be heated by causing the descending column of hot water to
heat the ascending column of cold water by conduction and radiation in such a
manner that the movement of the liquid is due alone to the addition and subtraction
of heat so that the novel feature of this part of my invention apart from the
process consists in causing the heat of the acting surface to induce the upward flow
of the water in contradistinction to the ordinary principle in refrigeration where
the current or flow is induced by a head or pressure. In ordinary refrigerating
apparatus several volumes of water are used on the one side of the acting
refrigerating surface to cool one volume on the reverse side of the surface, the
current being induced by a head or pressure, but in my invention the acting
surfaces whether plates or tubes, being placed vertically or nearly so perform their
duty when the volumes to be cooled and heated are equal. By the disposition of
the heating surfaces vertically or nearly so, the natural tendency of liquids to rise
on becoming heated and to fall on becoming cooled is brought into play. This
mobility of the liquid against the acting surfaces induced by heat and not by
the current of a head or pressure forms a very important and distinct feature of
this invention and it also provides for the prevention and the removal of incrus-
tation for the flow against the acting surfaces being induced by temperature and
not by current all the difficulties arising from viscosity which form the great
obstacle in ordinary refrigerating are overcome and the liquid in contact with the
acting surface instead of adhering to it is in every case in a condition of much
greater mobility than the liquid not in such contact and the current against the
acting surface is relatively intensely active while the movement of the whole body
of water or the mean movement of the separate particles is very slow for instance
not more than an inch in two or three seconds. This very slow traverse or current
permits of the acting surfaces being so far apart as to furnish ample room for the
brushing and cleaning of the surfaces and the removal of the deposit or any
incrustation. At the same time the vertical disposition of the surfaces provides
for the deposited matter falling continuously into a colder and colder substratum as
before mentioned and thus prevents incrustation.
This principle of interchanging the heat from the water which has been heated
to the water to be heated is quite apart and separate from the use of chemical
reagents or of catching and returning the carbonic acid gas and although it is used
in conjunction with those parts of the invention this apparatus may also be used for
removing the temporary hardness, that is for the purpose of partly softening the
water.
The filter is made flexible and movable whereby it is provided with the means of
P

page_text: being on rigid and made of fibrous substance such as woven or twisted coconut
fibre are left free to move when agitated or rocked or twisted backwards and
forwards. In this way deposite matter as well as incrusted matter may he
removed from the filter when as before explained chemical reagents should not be
used or the supply of them should become stopped. Thus the difficulty arising out
of treatment in the heat from the tendency to incrustation when not prevented by
chemical reagents is overcome.
Preferred forms of apparatus constructed according to the above principles are
illustrated in the accompanying drawings in which
Fig. 1 shows a heat interchanger and depositor and filter in elevation and partly
in section.
Fig. 2 is a plan thereof with covers removed.
Fig. 3 shows another form of heat interchanger in which the filtering takes place
when the water is in a heated state.
Fig. 4 is a plan view thereof with cover removed.
Fig. 3 is a modified construction of apparatus on the same principle as that
shown in Fig. 3.
Fig. 6 is a cross section thereof on line 1, 1, Fig. 5.
Fig. 7 shows a form of heat interchanger with means for adding chemical in the
heat and in which the boiling or heating apparatus is apart from the interchanger
and in the same vessel as the filter and depositor.
Fig. 8 is a section thereof on line 2. 2.
Fig.
9 is a vertical central section of a form of heater and filter which may or
may not be used with an interchanger and which is provided with means for moving
the filter.
Fig. 10 is a cross section thereof on line 3, 3.
Fig. 11 is a vertical and Fig. 12 a plan view of the device for providing and
mixing solutions of chemicals in definite quantity.
Fig. 13 is a vertical section Fig. 14 a plan view of a kitchen boiler with interiorly
fitted heat interchanger.
Fig. 15 is a vertical section of a heat interchanger with filter to be heated by
gas and suitable or hotels for domestic use.
Fig. 16 is a cross section on line 4, 4, Fig. 15.
Fig. 17 is a central vertical section of a gas lamp fitted with a water softener.
Referring to Fig. 1 the heat interchanger A. for large purposes may be con-
veniently formed by placing in a box or vessel a say of wood a sheet or sheets b
of metal (say of tinned steel, copper or galvanized iron) in such a manner as to
divide the box a into two parts, the one part being for the upward flow and the
other for the downward flow, the plates being either plain or ribbed to prevent
buckling. The water in the cold state euters at or near the bottom and becomes
heated in ascending to the top where it is further heated or boiled as the case
may be by the heater and then descending on the opposite side of the plates
becomes cooled in imparting its heat to the ascending column. The water in
ascending having attained to very near the boiling point would require hut a
few degrees of heat added to cause nrtual ebulition, the water line being pre-
served at a few inches above the top of the plates. Any steam forming may be
condensed in a condensa box e open at the top at d but formed to dip below
the surface of the water or to where it is below the boiling point on the reverse
side to the heating apparatus D. A condense water pipe e is provided to run
off the condense water downwards and out through the side of the box.
Now if the vessel be say 9 ft. high about 3 ft. in brendlth and 2 ft. 6 ins. in
depth, the conducting plates may be placed depthways vortically in the vessel.
If the plates occupied two feet of the depth there would be six inches remaining
of the depth and if the plates were eight feet high there would remain one foot ou
the top for water and vapour space, the vessel being provided with a loose lid.
The plates & may be connected in pairs with strips of rolled metal having chases

page_text: rolled or formed in them to receive the edges of the plates so that they form Ụ
or V shaped plates two feet deep. These plates are attached together at their
other ends either by wood strips or by strips of metal so that they form a continuous
plate bent backwards and forwards the depth of the bends being two feet. The
end plates are secured to the end sides of the vessel and the joints at bottom made
good with wood packing and suitable cement so that the vessel is thus divided into
two parts vertically.
If the depth of the vessel be 2 ft. 6 ins. there would thus remain 3 inches on the
ascending side and 3 inches on the descending as a general supply space to supply
the U shaped spaces on both the ascending and descending side.
Thus the vessel is divided by the U shaped plates into U shaped water spaces
or chambers, the sides of which heat and cool the ascending and descending
columns of water respectively.
Thus the water on rising and becoming heated parts with its excess of carbonic
acid, and the salts of lime and magnesia become carbonates by the time the boiling
or point of highest temperature is reached and the excess of carbonic acid being
driven off in the heat these salts of lime and magnesia are precipitated and fall to
the bottom on both the ascending and descending sides. If the width of the
U shaped spaces is two inches the box would contain about 300 sq. ft. and if only
one inch, double that quantity. The upward and downward flow of the water
being gentle allows the deposition of the sedimentary matter to take place.
The dimensions of the apparatus vary according to result required and the
conductivity of the material used.
The cooled water passes by the pipe to the depositing chamber B in which is
the filter C. In Fig. 1 the filter is composed of a layer of coke or suitable solid
filtering material g supported on a grating from which hang fibres; preferably
cocoanut or coir fibres in suitable quantity to retain the solid suspended particles in
the water while allowing the latter to pass through. Below the grating there
may be any suitable number of inclined plates & carrying fibres hanging from their
under sides and arranged so that the water passes between the plates, the latter
being placed at a sufficiently steep inclination to allow sediment falling on them to
roll or slide off into the bottom of the vessel B. are mud valves placed in
this and other forms of apparatus at the lowest point of all mud collecting
spaces.
In Fig. 1 the heater D consists of a coil of pipe through which steam is
passed.
The apparatus shown in Fig. 3 differs from that shown in Fig. 1 in its general
construction and in having the fibre filter contained in the same vessel as the heat
interchanger and the heater, the said fibre filter being so placed that the water
passes through it in the heated state.
The heat interchanger here consists of a number of pipes m fixed upright or
placed vertically in a vessel having a double bottom n the higher being
perforated to receive the pipes m. The water is made to enter through pipe e
below the double bottom and rising upwards through the pipes is gathered in
the hood o and becomes builed, passes through the filter and descends outside the
pipes and passes away through the outflow pipe :. The spaces between the pipes
at the top may be filled up in any convenient way. Necessary removable doors for
cleaning and such like are intended to be provided as well as any necessary fittings.
The tubes may be round, oblong, star shaped or of other shape and may be set up
separately or concentrically to form annular tubes.
The heater D here consists of an annular steam jet or series of jets by which
steam is radially blown into the water. The cylindrical screen limits the sphere of
boiling the water passing beneath the lower edge of the screen p passes then
through the cylindrical perforated plate with the filtering fibre thereon previous
to returning around the tubes m and being cooled by the ascending column of cold
water in said tubes.
In Fig.
the apparatus shown differs in construction from that in Fig. 3 in

page_text: having a filter of solid matter in place of the fibre filter the said solid matter being
supported between the screen p and the cylinder 4 (which is not perforated) on the
annular perforated false bottom 7. In place of pipes ma continuous sheet of
metal is employed bent in U shaped corrugations to form a tube as shown in
Fig. 6 supported on a bottom of similar shape to the outline of the tube 4.
Within the central space of the tube is an inverted cone & open above to receive
sediment, and tapering gradually to the bottom of the apparatus to which bottom
it is fixed being there provided with the mud valve,
In the apparatus shown in Fig. 7 the heater is placed in a separate vessel from
the heat interchanger, the former being placed in the same chamber as the filter
and depositor. A is the heat interchanger with the plate bent into a form as
shown in Fig. 8 or other convenient form to present large surface, closed below by
the bottom and enclosed within the vessel A. The price within the plate
forms the rising space supplied by the food pipe + and the spaer outside the plate
forms the descending space with the outlet. The heated water rises into the
chamber above the plate and in communication therewith and from this
chamber passes to the vessel B through the piperriving in the upper part of
said vessel. In the vessel B is the heater D'rind below the latter the filter which
here consists of a number of loosely woven fibre cloths or of one cloth wound
spirally suspended within the inverted trimeate come open below. Below the
cone is the truncated inverted conc?elo el below and open above forming a
depositing plate for receiving se:liment: outside the rom is the inverted conical
plate or cloth with fibre thereon, through or by which the water innst pass on its
way to the outlet pipe by which it returns to the vessel A to heat the a-cending
column of water therein. Perforated plates may be placed above the heater to
disperse the bubbles of steam and conline the elmlition to a great degree to the
water below said plates.
Where but slight interchange of heat is required the apparatus inay be con-
structed as in Figs. 9 and 10 this construction being suitable for purifying water to
be supplied to steam boilers. This arrangement consists of a cylindrical pressure
vessel placed vertically say 6 ft. more or less in height and of a diameter suited
to the capacity of the boiler placed preferably above the boiler with a pump
between the supply and the apparatus or between the latter and the boiler. The
top removable cover may he domes and about 1 foot in height, the bottom
removable cover and depositing chamber occupying together about 2 feet and
there would be 4 ft. remaining for the depth of the filtering chamber which may
consist of an anmilar space formed by or between the filtering medium or cloth and
the circumference of the cylinder. The filtering medium may be placed between
an inner cylinder and outer open eylinder or come the outer cylinder or cone
being less in diameter than the cylinder or pressure vessel or tapered to leave an
annular space for the chamber for the filtered water. The fibre filter may be
placed in the vertical cylinder and be formed of fibrous substance such as lemp
attached to a network, or course canvas, or frame of wire work the hemp being tied
or worked into the frame with the fibre outside so as to allow the water to pass
freely through the frame and the sedimentary or filtrable matter strained back by
the long fibre which fibre would fall close and form a kind of uap and yet lift and
allow the water to pass freely through the frame and not become blocked as au
ordinary filter cloth would do. The fibre muy also project inside and out, and the
filter may be freed from sediment or deposit by blowing in steam or foreing in
water in the opposite direction occasionally.
The fibre worked onto the network may also be rolled up being attached to
metal rods at top as shown and at bottom also if desired bent in coils, the top
coil being supported by the top removable cover and depending from hooks and the
bottom coil is connected with a stirrer the shaft of which could pass through the
centre of the hottom cover; or the upper coil or coils can be fastened at one end to
the centre cylinder and at the other and to the cylinder or cone the centre
cylinder Going made movable to be rocked by the rocking shaft. In this

page_text: way the sediment could be dislodged daily or continuously discharged from the
filter.
The shaft is shown attached to the cylinder and the latter is revolvably held
in the collar supported by the arms The cylinder serves for carrying up
the cold water entering through pipe e
The apparatus shown in Figs. 15 and 16 is adapted to be heated by a gas burner
similar to that of a small gas stove, or it may be heated by any other form of stove.
It consists of the outer cylinder t and the inner cylinder the latter terminating
above in the dome with chimney shaft . The annular space between the
cylinders and is closed below and divided into two annular spaces by the
corrugated plate. The inner space is for the rising column of cold water supplied
by a pipe e, the outer space is for the falling column of hot water; the annular
filter strains the water. The gas burner or lamp is for convenience placed
near the lower end but the heat is carried up and directed against the upper part
of the cylinder t¹ and the dome by the chimney t and conical deflecting plate (8.
is the gas supply pipe, is the outflow pipe. By placing draw off cocks at
different heights on the cylinder soft water at suitable temperature may be
obtained.
Fig. 17 illustrates a small water softener applied to a gas lamp suitable for house
and small purposes where no special kitchen boiler is made use of. It consists of a
vessel having an inverted cone shaped under side a to act as the lamp deflector
and a chimney also forming the heating surface. The stand or stem may be a
tube u containing an inner tube to form the upward flow, the downward flow
being the annular space between the two tubes. Thus water would pass upwards
into the receiving or heating vessel which would contain a filter and pass into
one division of the chamber and pass out from the other division having passed
through the filtering medium and become cooled on descending. Regulating taps
and fittings would also be used and the mixer or measurer if used may either be
separate or embodied in the apparatus. When the heating apparatus is apart from
the heat interchanger, and is intended to utilize the waste gases from the furnace,
a convenient form is built up of a stack of trays or troughs having undulated or
folded or U shaped bottoms and corrugated lids, the U shaped spaces forming the
passage for the waste gases which may be made to pass through or under the trays
from end to end, or backwards and forwards, being directed by directing plates and
chambers at the ends of the trays. The water could then drop from tray to truy
and become boiled and deposited the filtering and depositing chamber being also
apart. This construction will be readily understood without illustration.
It will be understood that these apparatus before described when used without
chemical reagents will operate to remove temporary hardness but if chemicals are
to be used a mixer is necessary for making the solution of the necessary strength.
This is represented in Figs. 11 and 12 as arranged for mixing the chemical reagent
with the water previous to heating the latter.
The measurer or mixer consists of a larger and smaller cylinder or several
cylinders evete. one within the other, the outer cylinder being sufficiently
strong to withstand the necessary water pressure and fitted with top and bottom
removable covers if necessary according to circumstances. The inner chamber or
cylinder v contains the caustic soda or alkali or other reagent and the outer cylinder
or cylinders serve for diluting the solution of the reagent. A regulated quantity
of water is made to pass into each cylinder, thereby forming and displacing so
much of the solution from the inner cylinder in proportion to the water passed
direct to the outside cylinders which latter water does not pass into the
vessel containing the soda. A saturated solution of caustic soda is thus caused to
flow from the inner cylinder r and is diluted in the outer cylinders until the dilution
is such that the definite amount of soda per gallon is added to the water auto-
matically.
The measurer may also be in duplicate the one part containing a saturated or a
strong solution and the other a weak solution, both parts being provided with

page_text: regulating outflow to the inner and outer chamber so as to relatively and
respectively admit the water to each. The two parts can also be set to represent
in the one an excess of sola in the outflow and the other an insufficiency and the
two can again be regulated so as to give the correct proportions that are established
by testing By the use of any desired number of combined chambers arranged
concentrically the one within the other and fixed to a general top and bottom and
fitted with regulating connections, between each chamber and the water supply,
each succeeding chamber may have more water added and so contain a weaker and
a weaker alkaline solution and give the means of adjusting to a nicety or as
correctly as practicable the exact number of grains added per gallon as a continuous
quantity.
The measurer may also be provided with sight holes and glass tubes or vessels to
give the means of observing the colour, density and general conditions of the
solution. Also test cocks and other necessary attachments may be provided. The
measurer may also contain a water meter to register the number of gallons passed
through and so indicate the time for recharging with the solution according to the
size of the chamber and quantity of solution added on charging.
into the
also supplies water alone to
respectively meet in one
corks in the pipes
When the soda
In the construction illustrated the weakened solution fulls by pipe
tank where the ball cock cuts off the supply of water to the vessels
during the time the tank is full. The water main
the tank and the outflows, from the tanks
main outflow pipe which may be the pipe. The
and are connected together so that their movements correspond.
or other reagent is to be added in the heat the pipe or or may pass direct
to the apparatus as shown at 8 in Figs. 3, 5 or 7 to mix the solution with the water
just previous to the boiling of the latter.
Referring to Figs. 13 and 14, for home or domestic purposes the boiler of the kitchen
range may have added to it or contained in it aml be converted into a heat interchanger
by limiting the water spaces that lie against the heating surfaces by placing a plate or
plates about an inch away or distant from the heating surfaces so as to partition off
a thin layer of water which becomes heated vertically an I rises on boiling. Another
folded set of U shaped plates bent backwards and forwards and placed so as to
divide the main body of the boiler into two parts and extending from above the
water line to near the bottom, divides the boiled water from the unboiled entering
at and on circulation, the boiled water would become cooled. The draw off
pipe being placed low down on the boiled water side, the water drawn or
passing out of the boiler will have been raised to the boiling point and softened
notwithstanding it may pass out at a temperature less than boiling.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed declare that what 1
claim is :-
For softening or purifying water
1. The method consisting in heating the water in such a manner that the carbonic
acid gas disengaged at or by intermediate temperatures is caused to pass through
the same water at higher temperatures until so much of it as remains unutilized for
assistance in the conversion of the uncarbonated salts into carbonates is ultimately
driven off at or near the highest temperature attained.
2. The method consisting in applying heat to a body of water so that the tem-
perature of or the heat given to, the water is greatest at the top and least at the
bottom whereby the action of the carbonic acid is attained in or substantially in the
manner stated.
3. The method consisting in causing heal to act upon water, prepared or other-
wise, when the same is in such position above a body of colder water that sediment
thrown out by the heat falls into such colder body of water for the purpose
Bet forth.
4. The method of heating a body of water having an ascending movement from

page_text: an inlet at a low level to an outlet at a high level in a chamber with vertical or
steep walls, greater heat being applied to the upper part of said body of water
whereby the sediment produced in the water as it reaches the upper level falls
into or through the unheated or less heated water in the lower levels for the
purpose set forth.
5. The method of transferring heat from the body of water heated to that to be
heated consisting in bringing said bodies of water into juxtaposition with a dividing
diaphragm arranged vertically or substantially so whereby the upward movement
of the water previously unheated and the falling movement of water previously
heated, are caused by the transference or interchange of heat whereby viscosity
against the diaphragm is overcome.
6. A heat interchanger having passages separated one from another by vertical
or substantially vertical diaphragms whereby heat is transferred from the falling
previously heated water to the rising previously unheated water substantially as
set forth.
7. A heat interchanger consisting of an upright case divided into two parts by a
partition formed of a plate or plates suitably bent to give large contact surface and
arranged vertically in the case substantially as and for the purpose set forth.
8. A heat interchanger consisting of an upright case with a number of vertical
tubes m fixed in a false bottom therein substantially as and for the purpose
herein described.
9. A heat interchanger consisting of an upright case having within it a space
partitioned off from the remainder by a bent or corrugated plate or plates with
false bottom thereto and arranged substantially as and for the purpose described.
10. The combination with the heat interchanger of the heater arranged to com-
plete the heating of the water previously heated by the interchanger substantially
as described.
11. A filter composed of fibres depending from a backing or plate perforated or
otherwise substantially as set forth.
12. The combination with a filter of a mechanical contrivance adapted to move
the material of said filter so that the solidifying of sediment in said filter is
avoided.
13. A filter composed of fibre cloth hung upon rods adapted to be moved with a
twisting or scraping action on the fibres whereby the solidifying of sediment on
said fibres is avoided.
14. Apparatus comprising in combination a heat interchanger, a heater, and
filter, arranged whereby their respective actions are successively performed as
herein described.
15. A mixer or meter for diluting water with a solution of a reagent, constructed
as herein described.
16. The combination with a kitchen boiler of the plates w¹³ arranged therein
substantially as and for the purpose described.
17. The combination of an annular vessel t¹ constructed as a heat interchanger
with lamp or stove to chimney t and flue to substantially as described.
18. The combination with a lamp of a vessel thereover having the conical base
forming a reflector, the filter in said vessel, the hollow column and the feed pipe
therein forming a heat interchanger substantially as and for the purpose set forth.
Dated this 7th day of March 1801
HERBERT & CO.,
18, Buckingham Street, Strand, London, W.C., Agents for the Applicant.