mprovements in the Clarification, Purification, and Softening of Water, Contaminated Water, or Sewage in the Preparation of Reagents, and in Apparatus for use therein.
Year: 1891

page_text: Date of Application, 24th Dec., 1891
Complete Specification Left, 24th Oct., 1892-Accepted, 24th Dec., 1892
PROVISIONAL SPECIFICATION.
mprovements in the Clarification, Purification, and Softening of
Water, Contaminated Water, or Sewage in the Preparation of
Reagents, and in Apparatus for use therein.
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:
:-
This invention relates to the clarification, purification and softening of water
in general containing mineral chemical or organic impurities so that such water
may be rendered fit for various uses such as for boilers or for any of the different
manufacturing or domestic uses, also to the treatment of contaminated water such
as sewage with a view to render the same harmless.
The invention consists in certain improvements applicable to various processes
or inethods of purifying, clarifying or softening water or contaminated water as
above stated, these improvements being principally connected with the aggregation
of the solid matters, both previously suspended solids and those thrown out of
solution thus preparing the precipitate for deposit and accelerating the action with
the separation of the precipitate quickly, with the separation thereof in what may
be termed a fractional manner so that useful parts of the sediment may be recovered
from the useless with the treatment of the sediment to destroy organisms, and
furthermore with the preparation of reagents.
The improvements consist first in making use of sedimentary matter in the act
of precipitation to cause the collection and separation from the water of the
suspended matters therein by the method namely of bringing this sedimentary
matter into the water to be treated and causing it to shower down or pass through
the water and so carry with it the suspended matters which are by this action of
the sedimentary matter caused to aggregate into larger particles. The heavier
parts of the sediment are thereupon separated from the lighter so that the heavier
sediment suitable for this precipitating purpose may be again carried upward apart
from the body of water treated to be used again upon another body of water in the
like manner, while the lighter sediment obtained in a more aggregate form is
easily deposited to be used again if necessary.
Certain waters may be clarified by the mechanical action of suitable heavy
sedimentary particles falling through them and so striking against and carrying
down the lighter particles which otherwise by their fineness would take an extremely
long time to settle, causing these light particles so overweighted to fall down quicker
than other light particles not so overweighted and so come in contact with the
latter and aggregate the lighter particles into larger or flocculent masses which fall
5 more quickly through the water and so separate out more rapidly-the action here
depends on the mechanical bringing together of light particles so that they form
heavier particles, this being done by the greater speed of descent given to the
uppermost particles by the heavy sediment introduced, without which every
suspended particle having approximately the same rate of descent will have to
0 pass along to the bottom which is the cause of the length of time required for the
fine suspended matters in water to settle and for the water to become clear.
Where however the nature of the suspended matter is such that it will not by
this action alone aggregate into larger particles the action of the falling heavy
sedimentary matter requires to take place in the presence of chemical action so
5 that the nascent solids in the act of being thrown out of solution adhere to the
sedimentary matter or to the finely separated matter carried down by the
sedimentary matter and thus build up the larger particles which this invention is
1 tunduse

page_text: I am aware that chemical action tends to produce an aggregation of particles
but such alone in the softening and purification of water is not sufficient for a
speedy result, the aggregation of particles is rendered more complete by the action
of the sedimentary matter added to the water under treatment for not only is the
upper part of the volume of water cleared of its lighter particles but these being
carried down more quickly than they would of themselves fall serve as nuclei for
the aggregation of the particles in the lower strata.
Where the water is being cleared by chemical action (for instance the temporary
or partial hardness removed by lime) the sedimentary action above described should
not cease before the chemical action ceases (except as hereinafter described) as
otherwise light particles would continue to be thrown out of solution without the
artificial nuclei being present for their aggregation and a milky water would probably
result.
It is also obvious that the mere stirring about or uplifting of former sediment
so that it becomes diffused in the water and again settles is not capable of the
action here described since such sediment contains matters of all degrees of weight
and of fineness consequently after the heavy sediment has settled, the fine will tend
to remain suspended.
The described action of what in comparison to the rest may be termed heavy
sediment, and the separation of heavy from light sediment after the action is
completed may be effected by the following method. The body of water treated
is caused to slowly descend and the sediment taken from the bottom of the vessel
in which this is done is brought in at the top to shower down through the descending
body of water. The rate of fall of the heavy sediment in excess of the rate of
descent of the water carries down the particles as they are thrown out solution as
well as those suspended until these on nearing the bottom are aggregated sufficiently,
that were the heavy sediment removed they would yet fall in a comparatively
short time by their own weight (which rate of fall is nevertheless still less than
that of the heavy sediment). At this point the body of water is diverted to flow
upward or laterally so as not to move in the same direction as the sediment, so
that the heavy sediment will separate from the lighter, as completely as may be the
latter having now, when rising upward, in order to fall to overcome the rising
stream of water. The rate of rise of the water is less than the rate of fall of the
heavy sediment, but greater than the rate of fall proper to the lighter sediment
by itself. Thus the heavy sediment falls upon the bottom of the vessel and there
remains until it is drawn out intermittently or continuously and returned to the
vessel at the top while the lighter sediment now in an aggregated state passes
upward with the rising water to a settling chamber which is preferably of the novel
principle hereinafter described or a filtering chamber.
With this method the reagent may be employed by adding it to the water before
or during the addition of the sediment.
Another method by which the sediment may be made to act on the water is by
vortical movement of the water with the sediment therein. Thus the water may
be caused to swirl in a vessel of a circular form of cross section the vortical
movement being produced by the direction of inlet and outlet flow, the sediment
drawn from the bottom being returned to the top. The action is here one of
aggregating only so that a depositing chamber is required in addition to the above
coupled with means for separating the useful from the useless sediment drawn
off previous to returning the former to the water under treatment.
Thus for waterworks a series of such circular vessels each fed with water from a
common supply may be used, the water swirled with aggregating sediment in these
vessels, overflows into a deep channel or trough in which that sediment which is
carried over with the water settles, being drawn off at the bottom. The water
passes onward from this trough through a filter formed of depending fibres
which is a self freeing filter bed the sediment aggregating on this falling down
to be carried away continuously from the bottom of the trough.
By this
process the continuous removal of the sediment as it is precipitated to

page_text: e bottom obviates entirely the bad effects of the usual means of filtering which
etain the impurities.
By this process also the ill effects of all precipitating processes for the treatment
f contaminated water or sewage which arise from the precipitate tending to form
aseous products and so rise again into the liquid from which they have been
recipitated are also avoided. For by preparation and use of potential sediment
lynamically potential by its increased weight to cause the rapid deposition of
uspended matters or matter thrown out of solution the depositing process is
ardened in such a manner that organisms or spores or seeds of river weed algae
c. are separated with great rapidity by the increased downpour of sediment so
that they may be constantly removed and continuously delivered and not lodge in
the filtering devices or arrangements. The object being to remove organisms so
rapidly that even in hot weather they may not have time given them to separate
from the sludge by reason of their power to form gas or a product of decomposition
to which they may attach themselves and so be floated upwards.
As heavy sediment I may use silica or magnetic oxide of iron which latter has
also an oxidising effect combined with lime or I may prepare a sediment from àlumina
ferric or from the water itself.
The refuse of the lime after the latter is made into lime water by the method
hereinafter described may also be used as a sedimentary matter.
The way in which such sediment may be treated or lime water sediment prepared
is to add silica or a compound of iron for instance in such a manner that the lime
uniting with the silica and iron may produce a heavy and quick descending
sediment which will carry down the lighter floculent matter and become separated
or less constantly and so not
by its superior gravity to be returned more
be lost.
I may produce the sediment required in the water under treatment by the following
novel method of treatment.
Supposing that a certain quantity of lime water is required for the treatment of
certain volume of water, the novel method consists in adding the whole of this
quantity of lime water to a portion only of the whole of the said quantity of water.
This will give a very large excess of lime after action on this portion of water
which may be done in a swirling vessel as described, a further portion of the whole
volume of water is added and the action continued.
In this manner the water is added in successive portions until the whole has
been acted on by the lime. The strong action in the first vessel will make a
sediment (aggregated if necessary on a little previously added sedimentary matter).
This sediment serves as nuclei for the next action and so on until the whole volume
of water has been acted upon in the presence of the said sediment and with the
continual automatic addition to the bulk of the sediment by aggregation of the
solids thrown out of solution.
This process may be conducted in a series of swirling vessels the water (first
portion) and lime water (total proportionate quantity) being added continuously to
the first vessel. The water overflows from the first vessel to the second, the
5 sediment being carried over with the water, here the second portion of water is
continuously added, the resultant water with sediment overflowing into the third
vessel where the third portion of water is added and so on through the series of
vessels until all the water has been added for the proportion of lime water.
The water may or may not be completely treated in such a series of vessels
0 passing thence to a depositing chamber if completely treated, if not completely
treated it may pass with the sediment which is suspended in it into the vessel
before described where it first descends in a body and then ascends to separate the
sediment into heavy and light.
Where the action is carried on under heat the vessels need not be circular as
5 the movement of the liquid will be induced by the heat and therefore vortical
movement is not necessary, the vessels may then be formed as compartments of
a tank with suitable heating apparatus. Here the carbonic acid if any driven off

page_text: by the heat will be returned at the end of the process to prevent reagents passing
off in a hydrated state in the water.
Where water requires to be treated by two or more different reagents or
coagulants for instance soda and lime, these are added in the whole amount of their
proportional volume to a part only of the proportional volume of the water to be
treated, that is to say the water to be treated is divided into two separate volumes
in the case of soda and lime one to receive the soda the other the lime. After these
chemicals have added separately in their respective volumes of water which may be
added in successive portious as before described, the two volumes may be mingled
and the process completed as far as regards the chemical action.
Also when the action is carried on in the partially heated state or both in the
cold and in the heat combined, the sedimentary matter may be caused to descend
first through a layer of water heated by a top heater (and also if necessary by a
heat interchanging apparatus whereby the outflowing water is cooled in parting
with its heat to the outflowing water). The under layer of water having an inlet
for water either at or near the bottom or midway up that is at the top of the
cold layer of water. In the latter case a directing cone could be fixed half way up
the vessel causing the water admitted near the top of the cone to descend in the
direction of the descending or falling sediment and afterwards to rise on the other
side of the cone and make its exit as either finished and filtered water or to be
further deposited and filtered in a separate vessel. This apparatus is intended to
deal with the clarification of water to be used first in the cold in a clean and partially
softened state and so suitable for refrigerating and condensing purposes and then
in the heat after leaving the condenser or refrigerator for boiler and other purposes
after complete softening. The advantage of the falling sediment after having
passed through the hot superstratum of water are obtained firstly by the coagulating
action of heat and the conversion of slimy sludge into coagulated sedimentary
matter.
The deposited sedimentary matter which is to be returned to again pass through
the water may be drawn off and carried upward by introducing a jet of water or an
inflow of water into the drain pipe to act as an injector to propel the current of
sludge water and carry it on to the top where it may meet the lime water and be
delivered at the top of the apparatus or cylinder.
A variation of this method is to propel the stream of water by a steam jet and
cause a rapid falling of sediment through lime water rendering the sediment
attractive or possessive of powers of attraction in consequence of being more highly
charged with lime &c., the apparatus being a hot process arrangement for preparing
the lime water and boiling the returned selected sedimentary matter with the lime
or lime water.
This invention also comprises a novel depositing apparatus. This apparatus
depends upon the principle of dividing a vessel into two chambers or parts, in such
a way that the sediment falling from the body of water passing through the
apparatus needs only to fall through a comparatively short depth of water say at
the maximum one inch or so and thereupon is not only completely precipitated
from the water but also passes out of contact with the body of water from which
the settling has been or is to be done. I thus obtain an extremely rapid settling,
the time being that required to enable particles to fall in the water one inch or so
since no particles require to fall further than this distance before they pass away
from the water which is to be clarified. The apparatus by which this may be
performed is characterized by the fact that the water to be clarified is passed along
under a system of protecting roofs which practically prevent all the sediment that
has fallen the required short distance through the water from coming in contact
with the water being clarified and substantially therefore divide the tank or vessel
into a sediment chamber and a clarifying water chamber from which latter,
sediment can and will pass freely into the sediment chamber but not return from
there.
Thus the apparatus may consist of a stack of pear shaped or diamond shaped or

page_text: roof shaped or shaped tubes, through or along which the water passes slowly.
These tubes when pear shaped or diamond shaped are slit along their lowest angles
so that as the sediment settles on the inclined sides of the tubes it slides out at said
slits and arrives outside the tube so that it cannot enter any other tube. The
water passes in at one end of the tubes and out at the other, the current is stopped
from passing in the interstices between the tubes by any suitable screen except
when roof shaped in which case the sediment always on the bottom of the tubes
slides from one roof on to another.
The same effect may be produced by a stack of inverted V shaped plates through
which the water current passes longitudinally so that the sediment having once
fallen onto any of the A plates does not afterwards, in its fall come into contact
with the water current.
A similar effect may be produced with A plates by placing each layer of plates
crosswise over the layer below and making slits in the apices of the plates so that
the current of water passes upward between the walls of the A plates. The
A plates are only slit along such parts as are directed under the A plates next
above them, they are left solid just below the valley between two of the A plates
above them so that the descending sediment having once fallen onto the outside of
any A plate does not enter the inside of any other A plate.
In none of these constructions does the clarifying water move in contact however
undisturbing with sediment precipitated on the plates, so that it is freed from its
sediment in the space of time that the latter requires to settle through the depth of
any pipe or A piece.
A self freeing filter cloth made, for instance, of coarse cocoa nut or coir fibre
may be suspended before the ends of each stack of plates or pipes.
The sediment falling to the bottom of the tank may be continuously removed.
When the nature of the water is such that oxydation of matters contained
therein is requisite the tubes or plates may be made of black iron and may be extra
oxidised by burning after being shaped or they may be made of earthenware or a
mixture of iron compounds or oxides and earthenware and shaped for stacking
upon one another to form the necessary construction to divide the tank into
sediment and water chambers as previously described.
It will be understood that the apparatus and method chosen will depend upon
the nature of the water to be treated and the qualities which the resulting treated
water is desired to possess the general objects being to cause an aggregation of the
solid particles by means of sediment so that such particles may be in a state for
quick deposit, the incidental secondary objects are the preparation or obtaining of
a suitable sediment and the fractional precipitation of the sludge according to the
relative weight of its components, by which the heavier sediment may be obtained
for use again or by which the valuable parts of the sludge may be obtained separate
from the useless.
This latter feature is applicable to the treatment of sewage in which the
albumenoid matter useful as a manure forms a large amount, but so small a
percentage of the whole sludge that the sludge containing it is valueless.
By conducting the process with a smaller proportion of lime than is generally
used, a useless sludge is obtained and one comparatively inoffensive as containing
but little of the albumenoids, this containing the heavy sediment may be removed
to be used again as sedimentary matter after a purifying treatment if necessary.
The lighter Hoculent matters and each of the albumenoids as are left in solution
pass away with the water and are then removed by an oxydising matter such as
polarite or oxydising influence and are obtained as a separate sludge. The polarite
or iron ore or alumina ferric (ferric sulphate of alumina) may be 'ecovered and
used again in some cases.
The oxydising matter can be arranged in slit pipes etc. as before described or in
trays, the water whether sewage or any other contaminated water being passed
through or over said trays.
These trays may be constituted as a self delivering filter bed by providing a

page_text: series of inclined plates dipping into the trays which receive the sediment. The
sediment collecting in such trays passes along the plates from tray to tray as each
tray fills. Each tray may contain a perforated false bottom through which the
water to be filtered passes upward through the sedimentary matter in the tray.
This part of the invention relating to the preparation of lime water is intended
to render it practicable to conduct the softening of water as far as the use of lime
is concerned without the employment of large lime water tanks where the lime
water is prepared intermittently or occasionally and in the place of such lime water
tanks and intermittent process to substitute the continuous system requiring only
comparatively small tank room for the lime preparation. And not only so but to
render it possible to apply the lime softening process to small apparatus for domestic
and other purposes where the intermittent process of preparing lime water would
be too troublesome and impracticable. The improved process further enables the
whole strength of the lime to be profitably employed.
Lime being prepared by burning from the limestone and chalk formations of
necessity contains shells more or less broken up of different sizes and forms and
varying as regards solubility. Thus when cream of lime and water are mixed
together in this ordinary way the more soluble parts at once cause the greater part
of the saturation leading the more insoluble lime to strengthen the lime water to
the full saturating point. The object of the present process is exactly contrary to
this, that is to say the less soluble parts of the lime are submitted to the water
first and then the soluble parts added to complete the saturation. This is accom-
plished by submitting the spent lime or the less soluble part first to the action of
the incoming water and the more soluble lime afterwards. In carrying this into
effect I conduct the process in the heat whenever possible either by placing the
lime preparing apparatus inside the main hot water tank (as may be conveniently
done when the hot process of treating water is adopted) or by heating the lime
water by means of a steam jet or any convenient method. When lime is treated
in the heat the ready settlement of the sedimentary matter is brought about by
reason of the hot water being less buoyant than cold and also by the solvent action
of heat dissolving the less soluble portions of the lime shells and producing a true
lime water containing very little suspended or undissolved lime.
I may also
employ a heat interchanging apparatus to transmit the heat from the water treated
with lime to the incoming or untreated water and when this is not practicable I
apply the hot process to the less soluble parts of the lime only.
I also in carrying my process into effect employ various apparatus according to
the quantity of lime to be treated and the size of the apparatus required. The
general principle being providing a stowage tank for the cream of lime so that a
small portion of the cream of lime may be washed into the lime water preparing
vessel to strengthen already partly prepared lime water from the spent lime.
A convenient form of apparatus is a vessel conical in shape with a small hole
at bottom placed inside a similarly shaped vessel fitted with an injector or a water
or steam jet nozzle opposing the hole in the inside vessel. These two vessels
placed in a deeper vessel also cone shaped and having the main water supply
entering at bottom while a smaller quantity of water enters by the jet pipe already
mentioned. Thus in action the incoming water rising upward in the space between
the second and third cone is met by the descending sediment from the cream of
lime solution which passes upward between the first and second cones and is
impelled by the jet of water before described. In this way the lime water
partially prepared in contact with the spent or more insoluble parts of the lime is
strengthened on reaching the top of the space between the cones alluded to by
the more soluble parts of the cream of lime solution while the heavier undissolved
parts descend through the partially prepared water and act finally upon the
incoming water.
Another convenient form of apparatus is a succession of vertical chambers
placed by the side of or in continuation of the cream of lime store vessel and
connected by suitable apertures at bottom and alternately heated with steam jets

page_text: or otherwise so that each alternate vessel may form a heating vessel and a depositing
ressel respectively so that the water on entering in a contrary direction or by the
ast chamber is met by the spent lime and the carbonates in the water continuously
leposited and the floculent matter procured for potential sediment.
In the cold process I combine with the apparatus described in the preceding
paragraph a tank or vessel in which a number of plates or disks are arranged to
receive the particles of lime and carbonate settling on them and allow these
particles to pass very gradually and always in contact with the water to the bottom
of the vessel where the water enters. By causing the water to pass in this vessel
in a circuitous direction and at the same time in a direction contrary to that in
which the lime particles tend to move the water comes first into contact with the
spent lime or nearly spent lime and as it gathers up lime in solution it continues
to come into contact with the stronger and stronger lime until it is eventually
saturated by the cream of lime.
The fully spent lime which is the result of this method is useful as
sediment" in the other parts of this process.
<
potential
Where the solution of the lime is secured by heat as aforesaid, the spent lime
descends in a precipitation tank whence it may be removed through a sludge cock.
In preparing solutions of readily soluble materials such as caustic soda I make
use of the difference in the density of the solution due to different strengths of
solution to obtain a solution of constant strength. The solution is made by
causing water to drop onto or pass over the reagent and thus to form a solution
which is received in a vessel in which a floating bulb similar to a hydrometer or
ball rises or falls or sinks as the density of the solution in which it fonts becomes
greater or less. The stem of this hydrometer moves a device preferably a string
or strings by which the inflowing water is guided so that the density of the
solution automatically determines the proportion of water which shall pass over
the reagent to the total volume which passes to the reagent dissolving apparatus.
That which does not pass onto the reagent dilutes that which has so passed so
that the total volume remains the same and proportional always to the water to
be treated while the automatic control of the hydrometer keeps the volume at the
same density that is to say at a uniform strength of solution.
The invention also comprises means for recording from time to time the state of
the water delivered from a water softening apparatus.
A tipping device gradually or periodically receives water from the bulk of
treated water and when filled tips such water into a series of small vessels preferably
of unequal size into each of which also a measured equal quantity of soap solution
of known strength is also tipped. Each vessel has a vertically movable lid.
When the liquid in the vessels is heated or air driven into it in each vessel in
which the soap solution is sufficiently strong in proportion to the amount of water
to more than neutralize the hardness therein, the liquid will froth and raise the lid,
thus setting in movement apparatus by which a record is made. This apparatus
may also be used for automatic regulation of amount of reagent added to the
water and in some cases such as for laundry purposes the process may be made
continuous.
The process of treating water also embraces a hot process in which the carbonic
acid gas is driven off partly by heating the water, such gas being retained for
returning to the water and in which the water is treated under pressure principally
When water is treated at a high pressure and
with an alkaline solution of lime.
0 temperature say of 50 or 60 lb. pressure and its equivalent temperature at boiling,
the salts of lime and magnesia are thrown down and may be separated without the
use of reagents. But the precipitation is accelerated when the water is made
slightly alkaline by a solution of lime, the alkalinity being afterwards removed by
returning the previously expelled carbonic acid gas.
5
The apparatus used by preference for carrying this process into effect consists of
an apparatus for preparing lime water previously described, a heat interchanging
apparatus, steam heating cones and a pressure cylinder with or containing filtering

page_text: The
and settling devices. The water previous to being pumped or passed into the
pressure cylinder is heated by the heat interchanging apparatus where the water
which leaves the pressure cylinder is made to heat the incoming water by parting
with its heat, thus becoming cooled. At the same time the carbonic acid gas
driven off from the former water is made to act upon the latter water to correct
any alkalinity or throw out of hydration, the free alkali in the treated water.
former or incoming water is then treated with lime pumped through the cone steam
heating apparatus on its way to the pressure cylinder and entering with great
velocity dashes upon plates placed above its water line and falls in showers. It is
directed by means of a truncated cone to near the bottom of the vessel and again
rises on the outside of the cone while the sediment is precipitated and falls down-
wards. The cone heating apparatus consists of a perforated pipe containing a
number of cones the end of one fitting into the base of the next leaving room for
play and for admission of steam, this perforated pipe again fitting into a jacketting
or outer pipe fitted with steam inlet and suitable screws and fastenings. The water
being forced equals rather more in velocity than its equivalent or steam pressure so
that the propelling power of the steam together with the velocity of the water
forces steam and water together into the pressure cylinder. This apparatus may
be used as a means of separating the salts of lime without any reagent when it is
desirable to do so and also without being in conjunction with a heat interchanging
apparatus.
Dated this 24th day of December 1891.
HERBERT & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Clarification, Purification, and Softening of
Water, Contaminated Water, or Sewage in the Preparation of
Reagents, and in Apparatus for use therein.
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 same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates to the clarification, purification and softening of water in
general containing mineral, chemical or organic impurities so that such water may
be rendered fit for various uses such as for boilers or for any of the different
manufacturing or domestic uses; also to the treatment of contaminated water such
as sewage with a view to render the same harmless.
It is impracticable, in the class of processes to which this invention relates, to
specify any one process which shall be applicable to all waters, since the process
must be varied not only in details but in essential particulars according to the
nature of the water or contents thereof and the result desired to be produced, that
is to say what, if any, of the contents of the water are to be removed or modified.
Keeping however the desired result and the nature of the water in view such of
the methods hereinafter described will be chosen as the case will require.
This invention contemplates an improved method of utilizing sedimentary matter
for the removal of suspended matters in the water, a method which I have termed
the shower" method.
The invention further contemplates the employment of this method, or a modifi-
cation thereof to the clarifying of water in which solids are in the act of being
thrown out of solution, or to the preparation of such a water for clarification.
The invention further contemplates a modification of the method of utilizing
sediment (more especially for use where nascent solids are formed) termed the
"swirling" method.
The invention further includes methods for preparing, in situ or otherwise,

page_text: suitable sediment for the purpose in view (I term this for convenience "potential "
sediment) separating that valuable in the process from that of no value therefor by
methods of selection.
The invention comprises also a system designed for rapid precipitation of sus-
pended solids which may be summarised as "settling under protecting roofs,"
certain modifications of the apparatus used therein being suitable for preparation
of and employment of potential sediment.
The invention also comprises methods of preparing lime water and solutions of
reagents of constant strength, and by automatic continuous or discontinuous
methods. Also methods of employing the said lime water or reagents.
By choosing such of the methods and combining them with due regard to the
nature of the water and the end in view and constructing apparatus on the principles
hereinafter set forth and explained, this invention may be applied to the clarification,
purification, or softening of any water, contaminated water or sewage, all which are
herein intended to be included in the term "water."
The improvements consist first in making use of sedimentary matter in the act
of precipitation to cause the collection and separation from the water of the sus-
pended matters therein by the method namely of bringing this sedimentary matter
into the water to be treated and causing it to shower down or pass through the
water and so carry with it the suspended matters which are by this action of the
sedimentary matter caused to aggregate into larger particles. The heavier parts
of the sediment are thereupon separated from the lighter so that the heavier
sediment suitable for this precipitating purpose may be again carried upward apart
from the body of water and treated to be used again upon another body of water
in the like manner and if desired treated to destroy organic matter, while the
lighter sediment obtained in a more aggregate form is easily deposited to be used
again if necessary.
Certain waters may be clarified by the mechanical action of suitable heavy
sedimentary particles falling through them and so striking against and carrying
down the lighter particles which otherwise by their fineness would take an
extremely long time to settle, causing these light particles so overweighted to
fall down quicker than other light particles not so overweighted and so come
in contact with the latter and aggregate the lighter particles into larger or
flocculent masses which fall more quickly through the water and so separate out
more rapidly. The action here depends on the mechanical bringing together of
light particles so that they form heavier particles, this being done by the greater
speed of descent given to the uppermost particles by the heavy sediment introduced
without which every suspended particle having approximately the same rate of
descent will have to pass along to the bottom which is the cause of the length
of time otherwise required for the fine suspended matters in water to settle and
for the water to become clear.
Where however the nature of the suspended matter is such that it will not
by this action alone aggregate into larger particles the action of the falling
heavy sedimentary matter requires to take place in the presence of chemical
action so that the nascent solids in the act of being thrown out of solution
adhere to the sedimentary matter or to the finely separated matter carried down
by the sedimentary matter and thus build up the larger particles which this part
of the invention is designed to produce.
I am aware that chemical action tends to produce an aggregation of particles
but such alone in the softening and purification of water is not sufficient for a
speedy result, the aggregation of particles is rendered more complete by the action
of the sedimentary matter added to the water under treatment for not only is the
upper part of the volume of water cleared of its lighter particles but these being
carried down more quickly than they would of themselves fall serve as nuclei for
the aggregation of the particles in the lower strata.
Where the water is being cleared by chemical action (for instance the temporary
B

page_text: or partial hardness removed by lime) the sedimentary action above described should
not cease before the chemical action ceases (except as hereinafter described) as
otherwise light particles would continue to be thrown out of solution without the
artificial nuclei being present for their aggregation, and a milky water would
probably result.
It is also obvious that the mere stirring about or uplifting of former sediment so
that it becomes diffused in the water and again settles is not capable of the action
here described since such sediment contains matters of all degrees of weight and of
fineness consequently after the heavy sediment has settled, the fine will tend to
remain suspended.
It should be a special object of the improved process to avoid agitation of the
water which simply breaks up the sediment.
The described action of what in comparison to the rest may be termed heavy
sediment and the separation of heavy from light sediment after the action is com-
pleted may be effected by the following method. The body of water treated is
caused to slowly descend and the sediment taken from the bottom of the vessel in
which this is done is brought in at the top to shower down through the descending
body of water. The rate of fall of the heavy sediment in excess of the rate of
descent of the water carries down the particles as they are thrown out solution as
well as those suspended until these on nearing the bottom are aggregated sufficiently,
that were the heavy sediment removed they would yet fall in a comparatively short
time by their own weight (which rate of fall is nevertheless still less than that of
the heavy sediment). At this point the body of water is diverted to flow upward
or laterally so as not to move in the same direction as the sediment so that the
heavy sediment will separate from the lighter as completely as may be the latter
having now, when rising upward, in order to fall to overcome the rising
stream of water. The rate of rise of the water is less than the rate of fall
of the heavy sediment, but greater than the rate of fall proper to the
lighter sediment by itself. Thus the heavy sediment falls upon the bottom of the
vessel and there remains until it is drawn out intermittently or continuously and
returned to the vessel at the top while the lighter sediment now in an aggregated
state passes upward with the rising water or laterally with the laterally moving
water, to or through a settling chamber which is preferably of the novel principle
hereinafter described, or else through a filtering chamber.
The heavy sediment may be returned direct to the water or may be carried to an
intermediate vessel to be there boiled or otherwise treated in any desired way for
destruction or removal of germs or preparation of the sediment in respect of the
qualities desired.
With this method the reagent may be employed by adding it to the water before
or during the addition of the sediment or to the sediment.
a represents a
A suitable vessel for this purpose is shown in diagram in Fig. 1.
cylindrical vessel tapering below and ending with a sludge cock b. c is the water
inlet. This enters at the base of the cone d, termed a selecting cone, and just above
the water inlet nozzle is the pipe e open above and below. f is a cylindrical or
tapered dividing wall. The heavy sedimentary matter" which lies in the cone d
is carried up with the incoming water and issues from the top of the pipe e, it
showers through the falling water inside the wall fand aggregates the lighter
particles. When the water with its lighter but now aggregated sediment passes
under the lower edge of the wall fand commences to rise in a, the heavy sediment
falls into the cone d while the lighter sediment is carried away with the water at
the outlet g or falls outside the cone d. In certain instances the water issuing at g
will be found to be clarified but if the nature of the water is such that it is not
clarified, but only the suspended matter therein "aggregated" then nevertheless it
will be found prepared for settling for instance in one of the settling apparatus
hereinafter described.
is a pipe for supply of reagent if desired.

page_text: In cases where the lighter sediment is preferable to the heavy or where a medium.
eight sediment is found practically the best aggregating medium the selecting
nes or equivalents are arranged accordingly in order to receive that class of
diment desired.
Fig. 2 shows a modified form of apparatus in which the pipe e being the sediment
take carries the sediment into a tank j where it is treated either by heat, by
eam, by lime or reagent desired introduced through pipe j' or washed or treated
yan oxidising agent or otherwise the treated sediment and water which was
mployed to carry up the sediment passing into the top of the apparatus through
ipe is another water inlet; by adjusting relatively the flow through e and c¹
ore or less sediment is showered through the water. is a mixing tray.
Fig. 3 also shows a modification of this apparatus in which the water is treated
oth in the heat and in the cold.
9,
The sedimentary matter is caused to descend first through an upper layer of water
cated by a heater inside or outside the apparatus, (or if necessary by a heat inter-
changing apparatus whereby the outflowing water is cooled in parting with its heat
o the inflowing water). In the drawing the cold water entering or drawn in at c
by steam jet draws also hot water in at land passes into pipe 2, the sediment
fallen into selecting cone d is thrown up pipe e into the treating tank where there
m² m² are inlet and outlet
s also a heater m for heating the sediment and water.
for steam. The hot water descends in the cone to about the dotted line n¹ and
issues at the under layer of water has an inlet c' about midway up, that is at the
In the latter case the
top of the cold layer of water indicated by dotted line n.
directing cone fis fixed half way up the vessel causing the cold water admitted
near the top of the cone to descend in the direction of the descending or falling
sediment and afterwards to rise on the other side of the cone and make its exit at g
as either finished and filtered water or to be further deposited and filtered in separate
vessel. This apparatus is suitable to deal with the clarification of water to be used
first in the cold in a clean and partially softened state and so suitable for
refrigerating and condensing purposes and then in the heat after leaving the
condenser or refrigerator for boiler and other purposes after complete softening ;
also for use in baths and wash-houses for producing hot and cold water in the same
apparatus.
The advantageous properties of the falling sediment are obtained on passing
Morcover the lime
through the hot superstratum of water by the coagulating action of heat and the
conversion of slimy sludge into coagulated sedimentary matter.
in the sediment is fully used up by being returned again and again.
Another method by which the sediment may be made to act on the water is by
vortical or "swirling" movement of the water with the sediment therein. Thus
the water may be caused to swirl in a vessel of a circular form of cross section the
vortical movement being produced by the direction of inlet and outlet flow, the
sediment drawn from the bottom being returned to the top. The action is here one
of aggregating only so that a depositing chamber is required in addition to the
above coupled with means for separating the useful from the useless sediment drawn
5 off previous to returning the former to the water under treatment.
The rotary action required may be produced in a vessel the general cross section
of which is circular whatever be the position of this vessel as regards inclination of
its axial centre, but a vessel with vertical axes is usually preferred.
Fig. 4 illustrates this swirling method in diagram, Fig. 5 being a plan view
0 thereof. kis a "swirling" vessel of general cylindrical form with inverted conical
bottom, c' is the inlet, the outlet. The tangential direction of flow at inlet and
outlet cause a vortical movement of the water.
Thus for water-works or where larger quantities of purified water are required
lt
an apparatus may be used as shown in Fig. 6 in elevation, Fig. 7 in plan and
55 Fig. 8 in cross section, Fig. 9 being a modification hereinafter referred to.
consists of a series of such circular vessels & each fed with water from a common

page_text: supply may be used, the water swirled with aggregating sediment in these vessels
overflows into a deep channel or trough k¹ in which that sediment which is carried
over with the water settles, being drawn off at the bottom to be returned by a small
water current by pipes el into the swirlers k, this small water current entering by
pipe c is divided being used also to return sediment from the bottom of the swirlers
by pipes e into the treating tank whence it passes again into the upper part of the
swirlers. is the lime water supply pipe. The water passes onward from the
trough through a filter 2 formed of depending fibres which is a self freeing filter
and through a settling and tray filter hereinafter described the sediment aggregating
on these falling down to be carried away continuously from the bottom of the
trough k¹.
The continuous removal of the sediment as it is precipitated to the bottom
obviates entirely the bad effects of the usual means of filtering which retain the
impurities.
The ill effects also of all precipitating processes for the treatment of contaminated
water or sewage which arise from the precipitate tending to form gaseous products
and so rise again into the liquid from which it has been precipitated, are generally
avoided, for, by preparation and use of potential sediment, dynamically potential by
its increased weight to cause the rapid deposition of suspended matters or matter
thrown out of solution-the depositing process is hastened in such a manner that even
organisms or spores or seeds of river weed algae &c. are separated with great
rapidity by the increased downpour of sediment so that they may be practically
removed and continuously delivered and not lodged in the filtering devices or
arrangements. An object and advantage of this process is to remove organisms so
rapidly that even in hot weather they may not have time given them to separate
from the sludge by reason of their power to form gas or a product of decomposition
to which they may attach themselves and so be floated upwards.
As heavy sediment I may use silica or magnetic oxide of iron or other oxide or
compound of iron which latter has also an oxidizing effect combined with lime or I
may prepare a sediment from alumina ferric or from the water itself or use any
suitable material.
The refuse of the lime after the latter is made into lime water by the method
hereinafter described may also be used as a sedimentary matter.
A. way in which such sediment may be treated or lime water sediment prepared
is to add silica or a compound of iron for instance in such a manner that the lime
uniting with the silica and iron may produce a heavy and quick descending sediment
which will carry down the lighter floculent matter and become separated by its
superior gravity to be returned more or less constantly and so not be lost.
I may also produce the sediment required in the water under treatment by the
following novel method of treatment.
Supposing that a certain quantity of lime water is required for the treatment of
certain volume of water, the novel method consists in adding the whole of this
quantity of lime water to a portion only of the whole of the said quantity of water.
This will give a very large excess of lime after action on this portion of water
which may be done in a swirling vessel as described, a further portion of the whole
volume of water is added and the action continued. In this manner the water is
added in successive portions until the whole has been acted on by the lime. The
strong action in the first vessel will make a sediment (aggregated if necessary on a
little previously added sedimentary matter).
This sediment serves as a nucleus for the next action and so on until the whole
volume of water has been acted upon in the presence of the said sediment and with
the continual automatic addition to the bulk of the sediment by aggregation of the
solids thrown out of solution.
This process may be conducted in a series of swirling vessels the water (first
portion) and lime water (total proportionate quantity) being added continuously
to the first vessel The water overflows from the first vessel to the second, the

page_text: sediment being carried over with the water, here the second portion of water is
continuously added, the resultant water with sediment overflowing into the third vessel
where the third portion of water is added and so forth through the series of vessels
until all the water has been added for the proportion of lime water.
The water may or may not be completely treated in such a series of vessels
passing thence to a depositing chamber of completely treated, if not completely
treated it may pass with the sediment which is suspended in it into the vessel before
described and illustrated in Figs. 1 or 2 where it first descends in a body and then
ascends to separate the sediment into heavy and light.
Where the action is carried on under heat the vessels need not be circular as the
movement of the liquid will be induced by the heat and therefore vortical movement
is not necessary, the vessels may then be formed as compartments of a tank with
suitable heating apparatus. Here any carbonic acid driven off by the heat may be
collected in a hood or hoods to be returned at the end of the process to prevent
reagents passing off in a hydrated state in the water.
Where water requires to be treated by two or more different reagents or
coagulants for instance soda and lime, these are added in the whole amount of their
proportional volume to a part only of the proportional volume of the water to be
treated, that is to say the water to be treated is divided into two separate volumes
in the case of soda and lime one to receive the soda the other the lime. After
these chemicals have acted separately in their respective volumes of water which
may be added in successive portions as before described, the two volumes may be
mingled and the process completed as far as regards the chemical action.
This invention also comprises a novel depositing or settling apparatus. This
apparatus depends upon the principle of practically dividing a vessel into two
chambers or parts, in such a way that the sediment falling from the body of water
passing through the apparatus needs only to fall through a comparatively short
depth of water say at the maximum one inch or so and thereupon is not only com-
pletely precipitated from the water but also passes out of contact with the body of
water from which the settling has been or is to be done. I thus obtain an extremely
rapid settling, the time being that required to enable particles to fall in the water,
say one inch or so, since no particles require to fall further than through whatever
maximum distance which may be chosen before they pass away from the water
which is to be clarified. The above maximum of 1 inch is stated as being suitable
but may be widely varied according to the nature of the water and general condi-
tions of the process, size of the apparatus etc., the distance being increased in pro-
portion to the rate at which the precipitate will fall. The apparatus by which this
may be performed is characterized by the fact that the water to be clarified is
passed along under a system of protecting roofs which practically prevent all the
sediment that has fallen the required short distance through the water from coming
in contact with the water being clarified and substantially therefore divide the tank
or vessel into a sediment chamber froin which latter sediment can and will pass
freely into the sediment chamber but not return from there.
Examples of this novel method of settling are shown in Figs. 10 to 15 in
diagram.
Thus the apparatus may consist of a stack of pear shaped (Fig. 10) or diamond
shaped (Fig. 11) or roof or A shaped (Figs. 12 and 13) or other shaped tubes o
open below through or along which the water passes slowly. These tubes o when
pear shaped (Fig. 10) or diamond shaped (Fig. 11) or the like are slit along their
lowest angles or parts as at o' so that as the sediment settles on the inclined sides
of the tubes it slides out at said slits o' and arrives outside the tube o whereupon it
cannot fall into any other tube o. The water passes in at one end of the tubes o
and out at the other, the current is stopped from passing in the interstices
between the tubes by any suitable screen except when roof shaped (Figs. 12
or 13) in which case the sediment always on the bottom of the tubular passages
formed by or between the roofs slides from one roof on to another.
The same effect may be produced by a stack of inverted V shaped plates

page_text: through which the water current passes longitudinally so that the sediment
having once fallen onto any of the A plates does not afterwards, in its fall come
into contact with the water current this is more particularly shown in Fig. 12.
A similar effect may be produced with A plates by placing each layer of
plates crosswise over the layer below making slits 3 in the apices of the
plates and causing the current of water to pass upward within and through the
apices of the plates (Fig. 15 perspective view). The A plates are only slit
along their top edges at such parts as are directly under the A plates next
above them, they are left solid as at of just below the valley between two of
the plates above them so that the descending sediment having once fallen
onto the outside of any A plate does not enter the inside of any other plate.
Where part of the matter thrown out of solution is sufficiently light to rise
then the roofs are arranged as in Fig. 16, that is to say, with an additional
slit or opening o² at the uppermost part of each passage way but so placed that
falling sediment from above cannot enter such passage way.
It will be seen that in these constructions, when employed as described, the
sediment which has once passed down out of any tube or out of the water which lies
under any roof, does not pass in its fall into or through any body of clarifying
water in any other tube or under any other roof. In the slit-tube forms shown in
Figs. 10, 11 and 16 and to a less degree also in the "roof" forms as shown in
Figs. 13 and 14 the said sediment (once fallen from a tube) also does not even come
in contact with the body of water within any other tube or under any other roof.
It is thus obvious that especially in forms 10 and 11 and in a minor degree in the
other forms, a vessel containing any such system may be said to be divided into a
water chamber, being composed of the spaces A and a sediment chamber composed
of the spaces B.
A self freeing filter cloth made for instance of coarse cocoa nut or coir fibre may
be suspended before the ends of each stock of plates or pipes.
The sediment falling to the bottom of the tank may be continuously removed.
When the nature of the water is such that oxydation of matters contained therein
is requisite the tubes or plates may be made of black iron and may be extra oxidised
by burning after being shaped or they may be faced with oxydising material or
made of earthenware or a mixture of iron compounds or oxides and earthenware
and shaped for stacking upon one another to form the necessary construction to
divide the tank into sediment and water chambers as previously described.
Fig. 17 shows how the pear shaped tubes may be made fixed to a backing p
which being solid between the pipes but perforated within the pipes allows the
'water only to pass through the pipes. Fig. 18 is a plan view thereof. Fig. 19
shows several systems of such pipes in plan the water to be clarified entering
between the sets of pipes in the spaces qq and after passing through the pipes
issuing into the spaces rr; in either of these spaces there may be hung, if desired,
filter cloths. Figs. 20 and 21 are respectively elevation and plan showing roof like
protectors projecting from a certain partition p which supports them. pare holes
for passage of the water.
A perfectly distinct use may be made of these apparatus of the roof like kind as
shown in Figs. 12 to 14 since if instead of passing the water along longitudinally
under the roofs, the water is passed crosswise under the roofs or otherwise in such
a way that it is constantly crossing the falling sediment, the apparatus makes an
effective aggregator. To work on this plan the roofs could be made as in Fig. 22
open along their apices. If the water moves in the direction either of the arrow w
or ww2 in this figure it is clear that it meets and passes through falling showers of
sediment aggregated by or on the roofs themselves.
Plates or roofs arranged on this principle and placed in the compartment k¹ in
the apparatus shown in Fig. 9 they are not intended in this case primarily for
clarifiers but as aggregators, nevertheless their action would tend to clarify also by
reason of the better aggregation of the sediment which they produce.
It is practicable also therefore to arrange roofs in such a way that the sediment

page_text: delivered from the roofs, while not again coming into contact with water under the
roofs, is showered into the water before it passes under the roofs. Various
arrangements may be made to effect this, that shown in diagram in Fig. 23 (slightly
mcdified on the right and left of the figure) is effective. Fig. 24 is a plan view of
this figure in square form. Fig. 25 a diagramatic plan in circular form. The
water entering at s passes down and issues laterally under the inner edges of the
various roofs o passing out at the spaces o, all the sediment which becomes
deposited on the roofs o slides into the central column of water as yet unclarified
but after the water has passed under one or other of the protecting roofs sediment
from above falls no longer into it. The surplus sediment is drawn off at the bottom
through a sludge-cock or suitably reduced orifice. The clarified water passing
into the outer containing vessel is drawn off at s'. The water could also enter
below and pass upward before moving laterally under the roofs as more particularly
shown in the plan Fig. 25. This system of roofs is shown in Fig. 26 as combined
with the apparatus described in reference to Fig. 1 the water entering at c throws
up the sediment in the tube, falling therewith within the partition, and then passing-
upward to be divided laterally under the roofs o. The selecting cone is to be made
larger or smaller according to whether the sediment which falls off the roofs o is of
value as a "potential" sediment or not.
It will be understood that the apparatus and method chosen will depend upon the
nature of the water to be treated and the qualities which the resulting treated
water is desired to possess the general objects being to cause an aggregation of the
solid particles by means of sediment so that such particles may be in a state for
quick deposit, the incidental secondary objects are the preparation or obtaining of
a suitable sediment and the fractional precipitation of the sludge according to the
relative weight of its components, by which the heavier sediment may be obtained
for use again or by which the valuable parts of the sludge may be obtained separate
from the useless.
This latter feature is applicable to the treatment of sewage in which the
albumenoid matter useful as a manure forms a large amount but so small a.
percentage of the whole sludge that the sludge containing it is valueless.
By conducting the process with a smaller proportion of lime than is generally
used, a useless sludge is obtained and one comparatively inoffensive as containing
but little of the albumenoids, this containing the heavy sediment may be removed
to be used again as sedimentary matter after a purifying treatment if necessary.
The lighter floculent matters and such of the albumenoids as are left in solution
pass away with the water and are then removed by an oxydising matter such as
polarite or an oxydising influence, electrical or other, and are obtained as a separate
sludge. The polarite or iron ore or alumina ferric (ferric sulphate of alumina) may
be recovered and used again in some cases.
The use of the apparatus shown in Fig. 16 will also be found very beneficial to
separate rising impurities as well as falling sludge from the water.
The oxydising matter can be arranged in slit pipes etc., as before described or in
trays, the water whether sewage or any other contaminated water being passed
through or over said trays.
These trays may be constituted as a self delivering filter bed by providing a
series of inclined plates dipping into the trays which receive the sediment as shown
in the middle of Fig. 27. The sediment collecting in such trays t passes along the
plates from tray to tray as each tray fills. Each tray may contain a perforated
false bottom through which the water to be filtered passes upward through the
sedimentary matter in the tray. These trays may be arranged in a vertical column
as on the left or on the right of Fig. 27. I may further combine the filtering
trays above described with the protecting roofs so that the water after passing
under the roofs passes through the filtering or oxydising medium in the trays, these
are shown in Figs. 7, 8 and 9 and as applied to the circular or radial apparatus
(Fig. 26) in Fig. 28. Fig. 28 represents an apparatus designed for domestic
purposes or where but comparatively small quantities of water are desired. The

page_text: uptake e partition selecting cone d and inlet care arranged as before described.
The partition may be perforated where the apparatus is small and a swirler or
other aggregator is necessary to commence the chemical process. The protecting
roofs o are a combination of the form Fig. 26 with the form Fig. 12 or Fig. 13.
They are shown in detail in cross section in Fig. 30 and in front view Fig. 31. The
whole circular set is shown in plan in Fig. 29. If moulded in earthenware or other
suitable material to have also the horizontally lying annular part u and the upturned
flange and if they are stacked together, with a series of interspacing rings w
perforated for passage of liquid, then the space outside said rings v and inside the
Hanges u will form an annular tray for oxydising or filtering matter equivalent to
the trays t.
The part of the invention relating to the preparation of lime water is intended
to render it practicable to conduct the softening of water as far as the use of lime
is concerned, without the employment of large lime water tanks where the lime
water is prepared by hand intermittently or occasionally and in the place of such
lime water tanks and intermittent manual process to substitute the continuous or
automatic system requiring only comparatively small tank room for the lime
preparation. And not only so but to render it possible to apply the lime softening
process to small apparatus for domestic and other purposes where the intermittent
manual process of preparing lime water would be too troublesome and impracticable.
The improved process further enables the whole strength of the lime to be
profitably employed.
Lime being prepared by burning from the limestone and chalk formations of
necessity contains shells more or less broken up of different sizes and forms and
varying as regards solubility. Thus when cream of lime and water are mixed
together in the ordinary way the more soluble parts at once cause the greater part
of the saturation leaving the more insoluble lime to strengthen the lime water to the
full saturating point. The object of the present process is exactly contrary to
this, that is to say the less soluble parts of the lime are submitted to the water first
and then the soluble parts added to complete the saturation. This is accomplished
by submitting the spent lime or the less soluble part first to the action of the
incoming water and the more soluble lime afterwards. In carrying this into effect
I conduct the process in the heat whenever possible either by placing the lime
preparing apparatus inside the main hot water tank, (as may be conveniently done
when the hot process of treating water is adopted) or by heating the lime water by
means of a steam jet or any convenient method. When lime is treated in the heat
the ready settlement of the sedimentary matter is brought about by reason of the
hot water being less buoyant than cold and also by the solvent action of heat dis-
solving the less soluble portions of the lime shells and producing a true lime water
containing very little suspended or undissolved lime. may also employ a heat
interchanging apparatus to transmit the heat from the water treated with lime to
the incoming or untreated water and when this is not practicable I apply the hot
process to the less soluble parts of the lime only. It is preferable to carry on the
process at a uniform temperature of 130° to 140° Fahrenheit being a convenient
and suitable temperature, as at about this temperature the strength of the lime
water obtained is fairly constant and clarifies more readily than when colder.
I also in carrying my process into effect employ various apparatus according to
the quantity of lime to be treated and the size of the apparatus required. The
general principle being to provide a storage tank for the cream of lime, so that a
small portion of the cream of lime may be washed into the lime water preparing
vessel to strengthen already partly prepared lime water from the spent lime.
A convenient form of apparatus is shown in Fig. 32, a vessel a conical in shape
containing the cream of lime is placed inside a similarly shaped vessel a¹ to receive
the lime which is displaced from the vessel a through the pipe is a small
water inlet pipe to displace the lime, is a steam pipe to keep the lime in agitation
and prevent its settling. The vessels are contained in a larger vessel having
inverted conical diaphragms a dipping into trays a and below these diaphragms

page_text: flat diaphragms 23 with holes in them made by punching up a portion of the
plate as in Fig. 33, 10; is the main water inlet, removal outlet for the spent
lime.
By causing the water to pass in this vessel in a direction contrary to that in
which the lime particles tend to move the water comes first into contact with the
spent lime or nearly spent lime on the trays or plates 8 and as it gathers up lime
in solution it continues to come into contact with the stronger and stronger lime in
the trays until it is eventually saturated by the cream of lime in the vessel. and
issues at The fully spent lime which is the result of this method is useful as
'potential sediment in the other parts of this process.
"
"
In preparing solutions of readily soluble materials such as caustic soda 1 make
use in the difference of the density of the solution due to different strengths of
solution to obtain a solution of constant strength. The solution is made by causing
water to drop onto or pass over the reagent, and thus to form a solution which is
received in a vessel in which a floating bulb similar to a hydrometer or ball rises
or sinks as the density of the solution in which it floats becomes greater or less.
The stem of this hydrometer moves a device preferably a string or strings by which
the inflowing water is guided so that the density of the solution automatically
determines the proportion of water which shall pass over the reagent to the total
volume which passes to the reagent dissolving apparatus. That which does not
pass onto the reagent dilutes that which has so passed so that the total volume
remains the same and proportional always to the water to be tested while the
automatic control of the hydrometer keeps the volume at the same density that is
to say at a uniform strength of solution.
Such an apparatus is shown in Fig. 34 y being a vessel to contain in the com-
partment y caustic soda or other reagent and in the compartment y² the diluted
solution thereof. y³ is a water tank, the outlet y being over the partition y³.
y are strings or flexible pipes, y' the hydrometer, y³ is a lever connected to the
hydrometer stem and guiding the strings ye. The saturated solution passes out of
the compartment y' at the lip y. The hydrometer assumes a position according to
the density of the diluted solution in y' and causes the water dripping from y° to fall
either into the compartment y¹ displacing saturated solution or into y² diluting the
solution therein, the device tends therefore to maintain a constant strength of
solution in the compartment y².
The process of treating water also embraces a hot process in which the carbonic
acid gas is driven off partly by heating the water, such gas being retained for
returning to the water, and in which the water is treated under pressure principally
with an alkaline solution of lime.
When water is treated at a high pressure and temperature say of 50 or 60 lb.
pressure and its equivalent temperature at boiling, the salts of lime and magnesia
are thrown down and may be separated without the use of reagents. But the
precipitation is accelerated when the water is made slightly alkaline by a solution
of lime, the alkalinity being afterwards removed by returning the previously
expelled carbonic acid gas.
The apparatus of this kind for use for feeding a steam boiler is shown in Fig. 35.
It consists of an apparatus for preparing lime water previously described (not
shown) a heat interchanging apparatus or its equivalent, steam heating cones z and
a pressure cylinder with or containing filtering and settling devices. The water
previous to being pumped or passed into the pressure cylinder is heated by the
heat interchanging apparatus where the water in the bottom of the pressure
cylinder is made to heat the incoming water by parting with its heat thus
becoming cooled. At the same time the carbonic acid gas driven off from the
water at is made to act upon the finished water in the boiler to correct any
alkalinity or throw out of hydration any free alkali in the treated water.
former or incoming water is then treated with lime entering at and is driven by
the steam injector through the cone steam heating apparatusz on its way to the
pressure cylinder and entering dashes upon plates placed above its water line
C
The

page_text: and falls in showers. It is directed by means of a truncated cone to near the
bottom of the vessel and again rises on the outside of the cone while the sediment
is precipitated and falls downwards into the cone d whence it is drawn into the cone
heating apparatus through pipe. The cone heating apparatus shown in detail
on a larger scale in Fig. 36 consists of a perforated pipe containing a number of
cones the end of one fitting into the base of the next which rests upon lugs 12
thereon so as to leave room for play and for admission of steam, this perforated
pipe again fitting into a jacketting or outer pipe fitted with steam inlet
(Fig. 35) and suitable screws and fastenings.
The water being forced equals rather more in velocity than its equivalent of
steam pressure so that the propelling power of the steam together with the velocity
of the water forces steam and water together into the pressure cylinder. This
apparatus may be used as a means of separating the salts of lime without any
reagent when it is desirable to do so and also without being in conjunction with a
beat interchanging apparatus.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is.
1. The shower" method of employing sedimentary matter for the aggregation
of suspended and nascent solids or either of them in water, contaminated water or
sewage as hereinbefore described.
2. The "swirling" method of employing sedimentary matter for the aggregation
of suspended and nascent solids or either of them in water contaminated water or
sewage as herein before described.
3. The combination of "swirling" and "shower" methods as described.
4. The methods herein described for separating the sedimentary matter and
apparatus thereof as illustrated and set forth.
5. The modified methods of employing sediment based respectively upon selection
or treatment of the sedimentary matter as herein described and apparatus therefor
as illustrated and set forth.
6. The method of preparing lime water and apparatus therefor as described and
illustrated.
7. The method of controlling the strength of solutions of soda or other reagents
and apparatus therefor as described.
8. The gradual method of treating water with a reagent and the gradual and
separate method of adding two or more reagents as herein described.
9. The method described for effecting settlement of suspended matters in water
consisting in passing same under protecting roofs as herein specified.
10. The apparatus formed of slit tubes or of other protecting roofs substantially
as illustrated and described.
11. The method of arranging said roofs whereby the sedimentary matter is
utilized for aggregation by the shower method.
12. The method of employing the protecting roofs aforesaid or some of them for
aggregating purposes.
13. Toxydising or filtering trays constructed substantially as set forth.
14. The modified method and means of employing sedimentary matter under heat
whereby also hot and cold water may be received from the same apparatus sub-
stantially as described with respect to Fig. 3.
15. The combined form of radial apparatus described with reference to Fig. 28.
16. The form of combined apparatus described with reference to Figs. 6 to 8.
17. The method and apparatus for softening water under pressure substantially
as described with reference to Figs. 35 and 36.
Dated this 24th day of October 1899
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.