CERTAIN IMPROVEMENTS IN THE METHODS OF PURIFYING VEGETABLE AND ANIMAL OILS, FATS, AND TALLOWS, IN ORDER TO RENDER THOSE SUBSTANCES MORE 'SUITABLE' TO SOAP MAKING, OR FOR BURNING IN LAMPS, OR FOR OTHER USEFUL PURPOSES, PART OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO THE PURIFYING OF THE MINERAL OIL OR SPIRIT COMMONLY CALLED PETROLIUM OR NAPTHA, OR COAL OIL, OR SPIRIT OF COAL TAR
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, Ì, DAVID
WALTHER, of Angel Court, Throgmorton Street, in the City of London;
Merchant, -send greeting.
WHEREAS did. by my Petition, humbly represent unto Her present most
Excellent Majesty Queen Victoria that by communication from a Foreigner
residing abroad had become possessed of an Invention for "CERTAIN
IMPROVEMENTS IN THE METHODS OF PURIFYING VEGETABLE AND ANIMAL OILS, FATS,
AND TALLOWS, IN ORDER TO RENDER THOSE SUBSTANCES MORE 'SUITABLE' TO SOAP
MAKING, OR FOR BURNING IN LAMPS, OR FOR OTHER USEFUL PURPOSES, PART OF
WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO THE PURIFYING OF THE MINERAL
OIL OR SPIRIT COMMONLY CALLED PETROLIUM OR NAPTHA, OR COAL OIL, OR SPIRIT
OF COAL TAR;" and Her said Majesty, being willing to give encouragement to
all arts and inventions which may be for the public good, was graciously
pleased by Her Royal Letters Patent under the Great Seal of the United
Kingdom of Great Britain and Ireland, bearing date at Westminster, the
Twenty-third day of December. One thousand eight hundred and forty, in the
fourth year of Her reign, for Herself, Her heirs and successors, to give and
grant unto me, the said David Walther, my executors, administrators, and
assigns, Her especial licence, full power, sole privilege and authority, that
I or they, by myself or themselves, or by my or their deputies, servants or
agents, or such others as I or they should agree with, and no others, during
the term of fourteen years from the date of the said Letters Patent, should
and lawful might make, use, exercise, and vend the 'said Invention, within that
Price & 1

page_text: part of Her said Majesty's Dominions called England. Her Dominion of Wales,
nd Town of Berwick-upon-Tweed, in such manner as to me, my executors,
admistrators, and assigns, should seem meet, and as that or they should
enjoy whole profit and advantage arising by reason of the said Invention
during the term of fourteen years; and for that end Her said Majesty
requires and strio commanded all Her subjects whatsoever within England,
Wales, and Berwick-n-Tweed aforesaid, that they shall not, neither directly
nor indirectly, make, use, put, in practice the said Invention, or any part
thereof, nor in anywise countertit, imitate, or resemble the same, nor make
any addition thereto or subtraction therefrom whereby to pretend himself or
themselves to be the inventor or inventors thereof: and whereas the said
Letters Patent contain a proviso obliging me, the said David Walther, parti-
cularly to describe and ascertain the nature of the said Invention, and in what
manner the same is to be performed, by an instrument in writing under my
hand and seal, and to cause the same to be enrolled in Her Majesty's. High
Court of Chancery within six calendar months next and immediately after the
date of the said Letters Patent, as in and by the same (reference being there
unto had) will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
David Walther, do hereby declare that the nature of the said Invention is
described and ascertained in manner following, and by the aid of the Sheet
of Drawing hereunto annexed, that is to say:
The said improvements in the methods of purifying vegetable and animal
oils, fats, and tallows partly consist in passing a supply of high-pressure steam
through perforations in a plate of metal, so as to divide such steam into numerous
small currents which ascend and pass up through quantities of such oils, fats,
or tallows whilst the same are kept enclosed within strong close vessels, and
kept subjected to the compressure and temperature due to the high-pressure
steam, which is passed in divided currents as aforesaid through the oils, fats,
or tallows, and which steam is afterwards permitted to make its escape from
the close vessels through loaded safety valves; and by means of such divided
currents of high-pressure steam so passing through the oils, fats, or tallows,
whilst the same are retained under strong compression at an elevated tempe-
rature, and the steam escaping afterwards as aforesaid, the impurities which
give a disagreeable smell to the oils, fats, or tallows (or great part of those
impurities) will be carried away along with the escaping steam, so as to be
removed by degrees from the oils, fats, or tallows, leaving the same in a more
highly purified state than the same oils, fats, or tallows were before having
been heated in manner aforesaid with divided currents of high-pressure steam,

page_text: according to this part of the said improvements. And further, the said improve-
ments also partly consist in collecting and cooling or condensing the steam
which has so passed in divided, currents through the oils, fats, or tallows after
such steam has made its escape through the loaded safety valves, in order that
by so cooling and condensing the steam into a liquid state it may deposit. that
impure portion of the oils, fats, or iallows which the said steam had carried
nway with it through the loaded safety valves, or may deposit so much of that.
said impure portion as it may be desirable to collect. And by degrees, or
progressively. the oils, fats, or iallows are subjected to a stronger compressure
and higher temperature during the time whilst the divided currents of high
pressure steam are passing through in manner aforesaid. -in order that at first
the most volatile of the impure portions of the oils, fats, or tallows may be
carried away along with the escaping steam, and afterwards the less volatile
impure portions and the volatile portions so carried away may either be allowed
to dissipate in the open air along with the steam which is escaping through
the loaded safety valves (in case it is desired merely to get rid of such volatile
portions), or else by cooling and condensing the steam after it has escaped
through the loaded safety valves. The impure portions of oils, fats, or tallows
which have been carried away with that steam may be collected and preserved;
in case it is thought to be desirable to preserve the same, whether for use as
inferior or impure sorts of the oils, fats, or tallows, or else merely to avoid the
offensive smell that might be caused by allowing such volatile impure portions
to be dissipated, in the open air. By loading the safety valves of the closed
vessels more heavily from time to time the high-pressure steam (which is
passed in manner aforesaid in divided currents through the oils, fats, or tallows
contained in such vessel) must of necessity have its elastic force duly increased,
in order that the steam may be able to lift up the safety valves so as to make
its escape therent; wherefore the oils, fats, or allows will be subjected to a
greater and greater compressuré, and a higher and higher temperature. during
the time whilst the divided currents of high-pressure steam are passing
through the same, according as the safety valves of the vessels are more and
more loaded. because in all cases the elastic force of the high-pressure steam
which is passed in divided currents through the oils, fats, or tallows must be
sufficient to enable that steam to lift up the safety valves and make its escape
thereat. At the commencement of the aforesaid operation upon any quantity
of oils. fats. or tallows which is put into the close vessel aforesaid, the safety
valves thereof may be lightly loaded. in order that the compressure and tem-
perature to which the oils, fats, or tallows are subjected may be moderate.
And under these circumstances the steam which is passed in divided currents

page_text: through the oils, fats, or tallows will only carry away with it the more volatile of
the impure portions of the oils, fats, or tallows, and which portions, from their
volatile nature, may (in general) be expected to have had the chief influence
in giving an offensive smell to the oils, fats, or tallows, and which for that reason
are the portions most desirable to be got rid of, either by being dissipated in
the open air along with the steam, or by being cooled and collected merely to
avoid an offensive smell in the air, in case the impure portion so collected is
thought to be of no use or utility. And after the operation has been con-
tinued some time with the safety valves moderately loaded, then the load
thercon is to be augmented, in order that the oils, fats, or tallows may be
subjected to stronger compressure and increased temperature whilst divided
currents of high-pressure steam of a corresponding pressure and temperature
are passing through, and thereby such steam will carry away with it other less
volatile impure portions of the oils, fats, or tallows than those more volatile
impure portions which would be carried away with the divided currents of steam
which were passed through the oils, fats, or tallows whilst the safety valves
were more lightly loaded. And as the operation goes on more weight is to be
from time to time loaded on the safety valves, in order to subject the oils,
fats, or tallows to a progressively increasing compressure and temperature
whilst divided currents of high-pressure steam of corresponding pressure
are passing through, in order that they may carry away the, less volatile
impure portions, until most of those portions which have much influence
in giving to the oils, fats, or tallows an offensive smell are carried off
(or for the most part carried off), leaving the oils, fats, and tallows remaining
in the close vessels in a purified state, and only requiring to be drawn
off from such close vessels, and cooled and separated from water resulting
from the steam, and then filtered (as herein-after described), in order to
become fit for sale or use.
And for the more complete explanation of the operation above described,
I have hereunto annexed a Drawing of an apparatus which may be employed
for the performance of that operation, although the form and arrangement.
of the parts of the apparatus may be varied. A is the close vessel before
mentioned, wherein the oils, fats, and tallows are to be inclosed. In order
to undergo the operation, it must be of a sufficient strength to endure
a pressure of five or six-atmospheres without any danger of bursting; and
for that reason a cylindrical form with hemispherical ends, as represented
in the Drawing, is to be preferred. The vessel A should be made of copper,
or, if made of iron for economy, it should be lined with thin copper, so that
the oils, fats, or tallows will not be brought in contact with any iron,

page_text: because, if that were permitted. discoloration of the oils, fats, or tallows might
result from some slight oxidation of that iron. The cylindrical part of the
vessel A may be formed of one piece of metal, or of metal plate united 'by
rivetting, and its hemispherical ends may be united thereto by nuts and screws
passing through flanges; or the lowest hemisphere may be formed in the same
piece of metal, with the cylindrical part, or they may be firmly united together
by rivetting, and the upper hemispherical cover united by flanges, as shewn in
the Drawing B. a, b, is the loaded safety valve, applied to an opening at the
upper part of the vessel A. The upright stem of the valve B is pressed down
by what is called a steelyard lever a, b. whereof a is the fulcrum and the
lever arm whereon the weight C is hung: and by increasing or diminishing
that weight, or by moving it along the lever arm farther from or nearer to
the fulcrum a, the load which bears on the valve to hold it down can be
increased or diminished according to the well-known manner of regulating
safety valves for high-pressure steam apparatus. so that the valve will be kept
securely closed by the weight of the load which acts upon it until the high-
pressure steam acting beneath the valves acquires that force of elastic pressure
for which the load on the valve has been adapted. and then if the steam
acquires any excess beyond that force, it will lift the valve and make its escape
through the valve. The high-pressure steam is introduced by a pipe D at the
lowest part of the vessel A. being brought to the pipe D through a branch
and cock E by a steam pipe F from any kind of high-pressure steam boiler.
such as is commonly used for supplying high-pressure steam engines with the
steam wherewith they are worked, and which boiler must be capable of raising
or retaining the steam within it to a pressure of five or six atmospheres with;
out any danger of bursting.. that steam boiler being provided with safety valves
of its own in the usual manner of such boilers, and with a suitable feeding
pump for keeping it supplied with water. When the cock E is opened it will
admit high-pressure steam (which is brought from the steam boiler by the
steam pipe F) to enter at the lowest part of the vessel a, the interior of that
vessel being filled two thirds or three fourths full, with the quantity of oils,
fats, or tallows which is to be operated upon, and the steam so admitted
ascends and passes upwards through small perforations in a false bottom or
copper plate m, and is thereby divided into numerous small currents, which
ascend and pass upwards through the whole depth of the oils, fats, or tallows,
causing a great agitation therein, and subjecting the oils, fats, or tallows to the
action of the steam; and the steam, after having so ascended and passed
through the oils, fats, or tallows, collects in the upper hemispherical end of the
réssel A, and makes its escape therefrom by lifting and opening the loaded

page_text: safety valve. B, which valve must be kept loaded to such an extent as is suitable
for the due performance of the operation, or of the commencement or other
stage of the operation, as the case may be. The compressure and tempera-
ture to which the oils, fats, or tallows contained in the vessel A will be sub-
jected whilst the divided currents of steam are so ascending through the oils.
fats, or tallows, depends entirely upon the load on the safety valve B of that
vessel, because as soon as the steam which collects in the upper part of the
vessel A acquires a sufficient elastic force to enable it to lift up that valve the
same will open and allow all the surplus steam to escape, so as to prevent any
further accumulation of steam within the vessel A. notwithstanding that the
steam proceeding from the steam boiler has a stronger elastic pressure than
corresponds to the load that is at the time loaded on the safety valve B. It is
by virtue of which stronger pressure that the steam enters with force into the
vessel A at D. and then ascends through the perforated plate m, and then
through the oils, fats, or allows partly by that force, but still more by the
buoyancy of the steam. The pressure of the steam in the boiler should always
be kept so much stronger than the pressure to which the safety valve B is loaded.
as will enable the steam to rush forcibly through the cock E, and the opening
of that cock must be regulated to restrain the steam so as to enter with only
a moderate rapidity into the vessel A at D: and in order to divide the steam
into numerous currents the false bottom before mentioned is fixed in the
lower part of the vessel A at the dotted line m, and that bottom is a thin
copper plate pierced with a great number of small holes, through which the
steam ascends, and is thereby divided into numerous small currents. in order
to produce the most effectual action of the steam upon the oils, fats, or tallows
in ascending through the same. And note, the central part of the said false
bottom is not pierced with such holes, but a central circle of about one third
of the diameter of the exterior circle of the false bottom is left impervious.
all the holes in the false bottom being disposed around that circle so as to
occupy the annular space comprized between the outer circumference of the
false bottom and the circumference of that central circle. * The intention of
the impervious central circle is to prevent the agitation caused by the ascending
currents of steam from being too strongly operative in the central part of the
vessel A, lest it might cause the oils, fats, or tallows to be dashed up so high
within the hemispherical top of the vessel A as to occasion liquid drops
thereof to be carried out at the safety valve B along with the escaping waste
steam, whereas such escape of liquid drops of oils, fats, or tallows is not in-
tended, but only that the waste steam shall escape thereat, together with so
much of the more volatile and bad-smelling portions of the oils, fats, or

page_text: tallows, as the divided currents of steam. according to the pressure and tem-
perature, can so far separate as to carry the same away with the waste steam
in a state of solution, but which more volatile portions will nevertheless
separate (or partly separate) from the steam on their becoming liberated from
compressure, and cooled and condensed so as to reduce the waste steam to
water. The safety valve B is enclosed within a small valve chest at the top of
the vessel A. which chest receives all the waste steam or vapour escaping
from that valve. The stem of the valve passes up through a stuffing box in
the centre of the cover of the chest, and from the side of the chest a pipe G
proceeds to carry away all the waste steam and vapour which escapes through
the safety valve B. The pipe G may be conveyed into the chimney of the
steam boiler in cases when it is merely required to get rid of the waste steam
and vapour; but in order to make some use of the heat of the waste steam it
is better to convey the same into a casing H around a heating vessel 1, con-
taining that quantity of oils, fats, or tallows which is to be heated in prepara-
tion for being introduced into the vessel A at the next succeeding charge
thereof. The waste steam, becoming spread.out in the narrow space around
the vessel I, communicates heat thereto and to the contents thereof; and at
first, when the said contents are cold, and so long as they continue to be cold,
their coldness will cause the waste steam to be condensed into water, which
collects within the space between the casing H and the vessel 1, together with
the most volatile, and bad-smelling part of the oils, fats, or tallows, which the
waste steam may have carried away with it through the safety valve, B. K is
a cock and pipe for drawing off from that space (when required) all the con-
densed water resulting from such condensation of the waste steam, together
with all the liquid matters resulting from so much condensation as may take
place of the said most volatile part of the oils, fats, or tallows, and also any
small portion of the oils. fats, or tallows which may have been unintentionally
driven out in a liquid state (or in drops) through the safety valve B.
In con-
sequence of too great a rapidity of the ascending currents of steam all the
liquids so drawn off through the cock K and its pipe will run down into a
waste receiving vessel L. wherein the water will deposit at the bottom and
separate itself in part from the impure liquids resulting from the oils, fats, or
tallows, so that the latter may be collected for use if thought to be of any
value. or else to be got rid of by burning or otherwise if found to have an
intolerably offensive smell. M is a cock for drawing off the contents of the
waste receiving vessel ; and note, an escape pipe proceeds away from the
casing H at the highest part thereof, and at the opposite side thereof to that side
where the waste steam pipe G joins thereto; the escape pipe being always

page_text: open to the atmosphere will prevent any confinement of the waste steam
within the casing H.. The escape pipe g may be carried up through the roof
of the building.. into the open air, or it may be carried into the chimney
of the furnace of the steam boiler. As the heating vessel 'I and the contents
thereof become by degrees more and more hot from the heating action of the
waste steam in the casing H, less of that steam will be condensed, and a
greater part thereof will have to escape through the pipe g. From the bottom
of the heating vessel 1 a pipe i proceeds to the vessel A, with a cock j, which
being opened (when required) allows the charge of oils, fats, or tallows to be
transferred into the vessel A, being already in a heated state, and thereby
prepared to undergo the same operation as the preceding charge has under-
gone in the vessel A, that preceding charge when finished having been drawn
off from the lower part of the vessel A through the cock P and pipe p into
a large receiving vessel R. The pressure of the steam contained within the
vessel A will force the liquid contents of that vessel to flow out through the
cock P and pipe p into the receiving vessel R, and the drawing off should be
performed whilst the vessel A and its contents continue hot, and immediately
after the steam cock E has been closed; or if requisite. to cause, the contents
of the vessel A to run out therefrom through the cock P and pipe 2, the steam
cock E may be left partly open in order to continue to admit some steam into
the vessel A. And note, the cock P and pipe p may (if preferred) be made
to join directly to the bottom of the vessel, as shewn by dotted lines Z, instead
of branching off from the pipe D. as represented in the Drawing, which pipe D
in that case will be solely for the admission of high-pressure steam into the
bottom of the vessel A. As soon as the vessel A is completely emptied from
its charge (as will be shewn by the steam following through the cock P and
pipe p) then the steam cock E is to be shut (if not already shut) and the
safety valve B freely opened to allow all pressure of steam to subside, and then
the cock being opened the new charge of oil, fats, or tallows will run from the
heating vessel into the vessel A by gravity. S is the cock for drawing off the
contents of the receiving vessel R. And note, when it is required to be
completely cool and condense, those portions of the oils, fats, or tallows con-
tained in the vessel A, which portions have been carried away along with the
waste steam which has made its escape through the safety valve B (such
cooling and condensing being in order to collect all the liquid resulting from
such portions), then the pipe G should connect by branch and stopcock
with some kind of refrigeratory pipe immersed in cold water, or enclosed.
within another larger pipe or casing wherein a current of cold water is kept
flowing in a contrary direction to the flow of waste steam through the interior

page_text: refrigeratory pipe. or a worm pipe, such as is used for distillation, may be
employed for such refrigeratory pipe. The passage from the pipe G'into the
casing, 'H may be shut by a cock in that pipe if it is not thought advantageous
to allow any of the waste steam to go into that casing, and when such cock is
shut the whole of the waste steam must pass through the aforesaid refrige-
ratory pipe, so as to be cooled and condensed into à liquid state, together with
such portions of the oils, fats, or tallows as the waste steam has carried away
along with it in making its escape through the loaded safety valve. And the
liquid obtained by means of the aforesaid cooling and condensing being
collected in any suitable vessel will be a mixture consisting of water resulting
from the steam, and of oily liquids resulting from those portions of the oils,
fats, or tallows which the steam had carried away along with it as aforesaid,
and which oily liquids may be afterwards separate from the water by leaving
the mixture at rest in the vessel wherein it has been collected during a suffi-
cient time for the-water to settle to the bottom with the oily liquids floating on
the water, and then the latter may be drawn off to maintain the oily liquid's
separately in order to be reserved for such use as they may be fit for. And
note. a branch from the steam pipe D. which brings the high-pressure steam
from the steam boiler to the apparatus, may be joined to the casing H, with a
steam cock in such branch, in order to supply fresh steam into that casing for
that purpose of communicating heat to the heating vessel I, and to the con-
tents thereof whenever the waste steam which passes through the pipe G is not
permitted to go into the casing H. but is shut off therefrom by the cock in
that pipe, as before mentioned, in order that such waste steam may go into the
refrigeratory pipe aforesaid: for in such case, by opening the said steam cock
in the said branch of the steam pipe fresh steam will be admitted from the
boiler into the casing H; and by adjusting the opening of the said steam cock
a more or less rapid current of such fresh steam will be admitted into the
casing H in order to give heat to the heating vessel I, and to the contents
thereof. And note, in case of fresh steam being admitted into the casing H,
a safety valve may be provided suitable for closing the open passage of the
escape pipe when required, which safety valve being applied in place
to close the passage of the pipe g, and loaded with a suitable weight, will not
allow a free escape of steam from the casing H through that pipe g, as herein-
before described, but will retain steam within the casing H in a state of
greater or less compressure around the heating vessel I so as to give greater
heat thereto than would be given by the waste steam (or by the steam from
the boiler) in case the same was permitted to escape freely through the open
escape pipe g. as herein-before described. And by loading the said safety
valve more and more the steam can be more and retained in the casing h, and

page_text: ,consequently. the temperature to which the contents of the heating vessel I
.can be raised may be increased at pleasure until the said safety valve becomes
heated nearly to the same degree as the safety valve belonging to the steam
boiler is at the same time loaded (that is to say, loaded in each case in pro-
portion to the respective areas of the two valves), under which circumstance
if the said steam cock in the branch of the steam pipe is fully opened, the
steam which is retained in the casing H around the heating vessel I may
acquire an elastic pressure and temperature approaching towards that which
the high-pressure steam in the boiler at the same time possesses, so as thereby
to give a considerable heat to the contents of the heating vessel I, which
heat may be given according as is required to the said contents towards
the conclusion of the operation upon a charge of oils, fats, or tallows contained
in the vessel A, and immediately before the said contents of the heating vessel I
are to be transferred into the vessel A, in order to become a succeeding charge
therein, in manner herein-before described. For whereas the operation of the
divided currents of steam upon a charge in the vessel A is continued for a
considerable length of time, the heating action of the waste steam passing
through the pipe G into the casing H, and escaping freely by the pipe (in
the manner herein-before described) during the early part of that time, will
gradually heat the contents of the heating vessel I without any expenditure of
steam for so heating; and also during such early part of the operation on the
oils, fats, or tallows, the safety valve B of the vessel A being only lightly
loaded, it may be expected that only the more volatile and impure portions of
the oils, fats, or tallows will be carried away with the waste steam which
is making its escape through the safety valve B, and which volatile impure
portions having generally an offensive smell are less desirable to be collected,
or if collected should be by themselves, which they will be in the casing H (or
will be in part collected therein), so as to be drawn off therefrom by the
cock K into the vessel L so long as the waste steam is conveyed through
the pipe G into the casing H, in the manner herein-before described; and as
the process advances the more volatile and worst-smelling portions of oils, fats,
or tallows having been for the most part carried away therefrom, and either
got rid of by escaping into the air or else collected within the casing H, or
partly disposed of in one way and partly in the other, then the load on the.
safety valve B is increased as the operation goes on, in order that the steam at
increased pressure and temperature may be enabled to carry away with it
the less volatile portions of the oils, fats, or tallows, and which portions,"
if they are kept separated from the most volatile and worst-smelling portions
previously got rid or disposed of, as aforesaid, may be in some cases worth
collecting by themselves in some vessel separately from the vessel L, wherein

page_text: those said worst-smelling portions have been already, collected. For this
purpose the passage from the pipe G into the casing H is to be closed by the
cock before mentioned, and the other cock in the aforesaid branch of the pipe G
which lead to the refrigeratory pipe, as before mentioned, is to be opened, in
order that the waste steam may be cooled and condensed therein, together with
all such further impure portion of the oils, fats, or tallows as the stronger and
hotter steam will be able to so far dissolve as to carry away with it in making
its escape as waste steam through the safety valve B, and which portions, after.
being so cooled and condensed in the refrigerating pipe, will be collected in
the receiving vessel belonging thereto in the form of oily liquids intermixed
with the water resulting from the condensation of steam, And when the
waste steam is no longer admitted into the casing H so as to give heat to the
vessel I, then the steam cock in the branch before mentioned from the steam
pipe may be opened to admit fresh steam from the boiler into the casing H in
order to continue the heating of the vessel I. and its contents by means of that
fresh steam. And if it is desirable to increase the temperature of such
contents the safety valve of the escape pipe before mentioned may be applied
to close the passage through that pipe g, 'and that valve may be loaded so as
to retain steam within the casing H to a greater elastic force than the
atmospheric air is already explained, in order that the contents of the heating
vessel I may become heated as much as can be desirable by way of preparation
for transferring those contents into the vessel A. And note, it is obvious that
it steam of a strong elastic force is intended to be retained in the casing H
that the metal of the said casing, as well as the metal of the heating vessel I,
must be made strong enough to resist the utmost pressure that the high-
pressure steam in the boiler is ever intended to attain without any danger of
bursting. And note, the receiving vessel R, into which the contents of the
vessel A are to be discharged, is made large and deep, in order that the hot
oils, fats, or tallows, when they are let out of the vessel A through the pipe p,
may not boil over the vessel R in consequence of the violent ebullition which
takes place therein at the moment of discharging them from the pipe p, owing
to the high-pressure steam which is intermixed with the oils, fats, or tallows
expanding and making its escape from them as soon as it gets liberated from
the pressure which is endured within the vessel A.
For purifying vegetable and animal oils according to my said improvements,
I can begin with such oils in the must crude or impure state in which they are
to be found as current articles of commerce; but I prefer to begin with the
oils after the same have undergone the usual and well-known treatment with
concentrated sulphuric acid, followed by copious washings with water, in order

page_text: The
to remove as much as possible of the acid. Oil after having been so treated
is an article of commerce, and is commonly used for burning in lamps, and the
manner of so treating oil being no part of the present improvements, and
being well known, need not be herein described. Into the heating vessel I,
I put such a quantity of the oil as will be sufficient to fill the vessel A one
half or two thirds full, and by. admitting steam into the casing H around the
vessel I, the oil therein is heated gradually in manner already explained. Such
heating may be performed with waste steam which is making its escape from
the safety valve B of the vessel A (that is, in case the operation of steam in
going on therein), or if that waste steam is not so escaping, or is insufficient,
then fresh steam from the boiler may be admitted into the casing H. as already
explained. Lime water is poured into the oil after it has become hot, and the
oil is well stirred to intermix the oil and water as much as possible.
lime water is to be prepared with as much quicklime as it will hold in. solu-
tion, being a saturated solution, which must be in a transparent state when put
into the oil, the quantity of such saturated lime water being about one tenth of
the quantity of oil. The mixture of oil and lime water is to be run down from
the heating vessel 1. through the pipe and cock j, into the vessel A, the
steam cock E being shut, and the safety valve B being fully opened, in-order
to permit the said mixture to enter freely into the vessel A; then the cock j is
shut, and the safety valve B is closed and loaded by the weight C at the
rate of about what is called two atmospheres, so that the steam which is about
to be admitted into the vessel A can only be accumulated therein until it
acquires twice as much elastic force therein as the atmospheric air without,
for after that the steam will be able to lift the safety valve B and make its
escape. Steam is admitted from the boiler into the lower part of the vessel A
at D by opening the steam cock E, but which cock must be only so much
opened as to admit the steam in moderation, so that the divided currents of
steam which pass up through the holes in the perforated bottom m, and which
then. ascend through the oil, will not cause the same to boil over in quantity
through the safety valve B, but the said currents of steam will dissolve, or
partly dissolve, and carry away, with them the most volatile and offensive-
smelling part of the oil, as already fully explained; and the load on the
safety valve is increased by degrees as the operation goes on, so that in the
course of four or five hours the load will become equal to four.atmospheres,
and the operation may be continued one hour therewith, until it is found, by
opening a peg-hole in the box B, and smelling the waste steam (which is
escaping at the safety valve B), that the same is no longer carrying off offensive
impurities as it had been previously doing, but that the waste steam is not of

page_text: a decidedly offensive odour, and only slightly tainted with impurities) and then
it will be known that the operation has been carried far enough. But as the
improvement of the purification of oil in this way is a matter of degree, the
operation may be stopped short of the utmost degree of purification which can
be obtained by the present improvements, according to the desire of the
operator to occupy less time in the occupation, or may he carried on to the full
extent, according to his desire to effect the greatest purification that can be
attained by the present improvements. In general, the time already men-
tioned being five or six hours, and a pressure of four atmospheres during the
last of those hours has been found sufficient to give a very unusual degree of.
purification to oils such as are in use in France; but in cases when the oils;
are not most impure to begin with, less time might be sufficient and less
pressure; or, on the other hand, if impurities are more fixed in the oil, then,
by increasing the pressure (suppose another atmosphere, that is, to five
atmospheres), and carrying on the operation for an additional length of time.
at such increased pressure (suppose another hour, making up six or seven-
hours), a still greater purification may be attained than could be attained in
six hours with a pressure of four atmospheres during the last of those hours;
and at the conclusion of the operation the steam cock E is closed (or nearly
closed) and the oil is drawn off inmediately afterwards by opening the cock P,
whereby the oil, intermixed with steam and also with some water, is discharged
through the pipe p into the vessel R, wherein the steam separates itself froni
the oil with great ebullition; and after the oil becomes cooled to a moderate
temperature, and the water has subsided to the bottom, that water is drawn off
carefully through the cock S and thrown aside, and afterwards the oil, by itself.
is run off into a filtering vessel, which. may be of any suitable kind, such, as is.
or may be used for filtration of oil. The filtering vessel which has been most
commonly used along with these improvements is a strong tub formed of wood,
the bottom being at least three inches in thickness, and perforated with a
great number of round holes bored with a tapering borer, so as to be about.
two inches diameter at top and only one inch at bottom. Those holes being
stuffed up with cotton wool, and that bottom so prepared, is covered over with.
a layer of sawdust of oak, or beech, or other hard wood (but not sawdust of.
fir or other resinous wood); such layer being about three inches in thickness,.
and over the sawdust a coarse canvas is spread to prevent the sawdust.
getting disturbed, and then a bottom of wickerwork is laid over the canvas to
keep it steady. The oil is kept filled into the tub about four feet deep on that
bottom in order that it may force its way down through the filter of sawdust.
and cotton, and the filtered oil which drips through is received in a vessel:

page_text: below, and is in a very improved state of purification, fit for sale or use, and
will be more suitable for soap making or for burning in lamps, or for other
useful purposes to which oil is commonly applied, than if such oil had not
undergone the process aforesaid. But note, no claim is made in this Specifica-
tion in relation to filtering the oil as any part of the new Invention, or to the
kind of filter which is to be used for that purpose; and note, it will be found
that the water which separates from the oil. when the same is drawn off into
the vessel R will have absorbed much impurity from the oil.
:
And for purifying fats and tallows the same course is followed, except as to
the addition of lime water; but the tallow, after being melted in the vessel I,
and heated therein (beyond melting if desired), is transferred through the
pipe and cock j into the vessel A. The safety valve B is, at first beginning
the operation with divided currents of high-pressure steam, loaded to one and
half atmospheres, and at about every half hour the load is increased gradually
until it gets to four atmospheres in the course of about four hours' time. The
waste steam being condensed and collected as herein-before described, either
in the casing I or in the refrigeratory pipe, will yield an impure greasy matter,
which may be used for some very inferior purposes where impurity does not
prohibit the use. The fat or tallow, when drawn off into the véssel R,
and separated from the water by drawing off the latter, will be in a very
improved state as to purification, and more fit for soap making, or for
making candles, or for other purposes to which tallow is usually applied,
than or was before having undergone the operation aforesaid.
And note, as
to the water above mentioned, from which the tallow is to become separated,
it will collect of itself within the vessel a from gradual condensation of the
high-pressure steam during the operation, or some water may be put into
the vessel A before the tallow is transferred into that vessel; for according as
the tallow is more impure it may be advisable to have more water in the
vessel A along with the fats or tallows during the operation than would collect
therein from the mere condensation of high-pressure steam.
And as to the purifying of mineral oil or spirit, commonly called petroleum or
naphtha, or coal oil, or spirit of coal tar, the same is to go through a like course
of operation as herein-before described in respect to vegetable and animal oils.
The volatile portion of such mineral oil or spirit which is carried off therefrom
along with the waste steam being collected (by cooling and condensing that waste
steam) is preserved in order to avoid nuisance from its dissipation in the air, or
preserved for such use or uses as it may be fit for. And note, impure concrete
vegetable oils; such as cocoa-nut oil, or soft and impure fats or tallows, being
treated in the same manner as above stated in respect to fats and tallows, will,

page_text: by the separation of their more volatile and impure portions, become more
concreted than they were before being so treated, as well as more purified,
whilst the said volatile portions being carried off along with the waste steam
may, by cooling and condensing of that steam, be collected, and will form
impure greasy or oily matter, which, if it be of a very offensive smell, will
-cause less nuisance when so collected than if it had been dissipated in the air;
and the same is also ready to be used for any such coarse and inferior purpose
as it may or can be applied to where its impure smell may not be a reason for
prohibiting its use.
。
.
And as to the dimensions of the apparatus represented in the Drawing,
the same may be made large or small, but proportioned with its several parts
one to another as in the Drawing, so as to be adapted to any size that
is desired, according to the extent of business that is required to be
carried on; and by way of example it will be sufficient to state that the
operation has been carried on in France with the vessel A twenty-one inches
diameter inside and four and a half feet high, the upper and lower ends being
hemispherical, the whole vessel A being made of rolled copper five-eighths of
an inch thick, the joints being made with double rows of rivets, the steam
cock at E having a bore of one inch diameter when fully opened, but
in working it was usually less than half opened, the other parts of the
apparatus being proportioned to such vessel A nearly as represented
in the Drawing, the high-pressure steam boiler which supplied three
such apparatuses with high-pressure steam, and which would have supplied
four such or more, being twenty feet long and two and a half feet diameter,
made of wrought iron, with two tubes disposed side by side under the said
boiler, and connected therewith in the manner of what is known as Woolf's
boiler, or Woolf and Edward's boiler. those tubes being over the fire. each
tube being twenty feet long and fourteen inches diameter wrought iron. A
small steam engine, supplied by steam from the said boiler. worked the feeding
pump to keep it properly supplied with water.
Having now described the said improvements. and the manner of per-
forming the same, I. the said David Walther, do hereby declare that the new
Invention whereof the exclusive use is granted to me by the said Letters
Patent, consists in the following particulars, videlicet :-
.
First, in the improvement herein-before described of passing a supply of
high-pressure steam through perforations by which it is provided into
numerous currents which are passed upwards through quantities of vegetable
or, animal, oils, fats, or tallows, whilst the same are enclosed within close
vessels, so as to be subjected to the compressure and temperature one to such
high-pressure steam, and which high-pressure steam, after having so passed in

page_text: such divided currents, makes its escape through loaded safety valves as wastè
steam, carrying away with it those more volatile impure portions. of the oils, fats,
or tallows which give an offensive smell thereto; or such waste' steam' carrying
away with it so much of such said volatile impure portions (which give an
offensive smell) as will leave the said oils, fats, or tallows in an improved state
as to purification after having been submitted (in the manner herein-before
described) to the operation of such divided currents of high-pressure, steam,
the said operation being performed upon vegetable or animal oils, fats, or
tallows either when the same are in their most gross, raw, or impure state .in
which they are commonly bought or sold as current articles of commerce;. or
else being performed when the same are in any states or stages of purification
to which they may be brought by means of any of those methods of purifying
vegetable or animal oils, fats, or tallows which are commonly known and
practised for that purpose.
Secondly, in the improvement herein-before described, of cooling, condensing,
and collecting, that waste steam which, after having been passed in divided
currents. through quantities of vegetable or animal oils, fats, or 'tallows, and
escaped therefrom through loaded safety valves as waste steam, carrying
with it yolatile impure portions of the said oils, fats, or tallows, as already
mentioned under the first head of improvement, in order that by so cooling,
condensing, and collecting (according to this second particular of improve-
ments) the said volatile impure portions may be collected (in order to avoid
nuisance by their dissipation in the air) or preserved for such use or uses as
they may be fit for.
Thirdly, in the improvement herein-before described, of separating the more
liquid portions of vegetable concrete oils or animal fats or tallows, leaving
the more concrete portions thereof in a purified state by passing divided
currents of high-pressure steam through quantities of such concrete oils, fats,
or tallows when the same are enclosed within close vessels, and subjected to the
compressure and temperature due to such high-pressure steam, the said. steam
afterwards escaping through loaded safety valves, and carrying with it portions
of such oils, fats, or tallows; and the steam after so escaping being cooled
and condensed, together with the said portions so carried with it, in order that
those portions when collected may be preserved, as the more impure portions
of the concrete oils, fats, or tallows; and also that by the separation thereof
from such oils, fats, or tallows, the remainder thereof will consist of the more
concrete portions in a purified state, so as to be more suitable for soap making
than without the said separation.
Fourthly, in the improvement herein-before described, of purifying the
mineral oil or spirit commonly called petroleum or naphtha, or coal oil, or.

page_text: spirit of coal tar, by separating therefrom the more volatile portion thereof
which chiefly contributes to give an offensive smell thereto (or separating
part of that said more volatile portion which chiefly contributes to give an
offensive smell), by passing divided currents of high-pressure steam through
quantities of such mineral oil or spirit aforesaid, whilst the same is enclosed
within close vessels, so as to be subjected to the compressure and temperature
due to such high-pressure steam, and which high-pressure steam, after having
so. passed in such divided currents, makes its escape through loaded safety
valves as waste steam, carrying away with it the more volatile portion afore-
said which chiefly contributes to give an offensive smell (or part of such
portion), leaving the remaining mineral oil or spirit aforesaid in a
purified state. Also preserving such volatile portion of the mineral oil or
spirit (as has been so carried away with the waste steam), that being done by
means of cooling. condensing, and collecting such waste steam in manner
herein-before described. so that the liquid resulting from the cooling and
condensing of such volatile portion (or part thereof) may be reserved for any
such use or uses as the same may be fit for: or if too offensive to be fit for
any use, then the nuisance which would be occasioned by the dissipation
thereof in the air may be avoided by so collecting such portion.
*In witness whereof. I. the said David Walther, have hereunto set my
hand and scal, this, Tenth day of May. in the year of our Lord One
thousand eight hundred and forty-one.
D. (L.S.) WALTHER.
Signed and sealed by the said David
Walther, in the presence of
CHARLES EVANS,
Gray's Inn.
AND BE IT REMEMBERED, that on the Tenth day of May, in the fourth
year of the reign of Her Majesty Queen Victoria, the said David Walther
came before our said Lady the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made in the fifty-fifth year of the reign of
His late Majesty King George the Third.
Enrolled the Twenty-third day of June. One thousand eight hundred