AN IMPROVED METHOD OF AND APPA- RATUS FOR RENDERING AND REFINING LARD, TALLOW, AND OTHER FATTY AND OLEAGINOUS MATTER
Year: 1869

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," No. 8, Southampton Buildings, London, Consulting
Engineer, for the Invention of "AN IMPROVED METHOD OF AND APPA-
RATUS FOR RENDERING AND REFINING LARD, TALLOW, AND OTHER FATTY AND
OLEAGINOUS MATTER."-A communication from abroad by Charles
James Everett, of Highwood Park, New Jersey, United States of
America.
Sealed the 23rd November 1869, and dated the 27th August 1869.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 27th August 1869.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
No. 8, Southampton Buildings, London, Consulting Engineer, do hereby
declare the nature of the said Invention for "AN IMPROVED METHOD OF
AND APPARATUS FOR RENDERING AND REFINING LARD, TALLOW, AND OTHER FATTY
AND OLEAGINOUS MATTER," a communication, to be as follows:-
The digester in which the fat is melted is a close vessel made of boiler
iron strong enough to resist a pressure of at least fifty pounds per square

page_text: inch, and is fitted with flues to insure a rapid reduction of the fat. This
digester is entirely enveloped in a tight iron vessel or jacket, which I will
style a retort. The said retort is in form the same as the digester, but
is larger than the latter in each dimension by about twelve inches, and
is so arranged in relation to it as to leave a space between the two
vessels of from six to eight inches wide, the two vessels being securely
stayed to each other. This retort and digester united make a double
vessel, which I will call the tank. In the upper end of this tank a man-
hole is made, through which the fat is introduced into the digester, and
which is provided with a steam-tight cover; and fitted with the necessary
mountings to secure it against the internal pressure, and in the side near
the bottom of the said tank a similar hole is made similarly covered and
mounted through which the refuse is removed. This tank is set in
brickwork over a furnace and supported by suitable bearing pieces.
The whole bottom of the tank is exposed to the action of the fire, and
the flues leading from the furnace to the chimney rise in a spiral
direction around the tank. In the inside of the digester is a pipe, the
upper end whereof terminates in a hollow socket joint, by which it is
connected to the delivery pipe, and by which the lower end thereof is
left free to rise and fall. The lower end of this pipe is fitted with a
float and a foraminous nozzle; the float keeps the nozzle near the surface
of the melted fat, rising and falling with it. By means of this pipe the
: melted fat is drawn out of the digester as fast as it is rendered by the
pressure of the steam, the pipe being fitted with a cock by which the
flow of the fat is regulated. In addition to the stays the retort is
-secured by means of long stay bolts fastened to the top and bottom.
.After the tank has been set the digester is charged with fat, and the
retort is filled about one-third full of water. The fire is then lighted in
the furnace. Both digester and retort are fitted with a steam gauge
.to indicate the pressure in the respective vessels. In treating offal I
put a little water on it, but usually there is no water put in the digester
save what is contained in the fat itself, which will vary in different kinds
of fat. The tank or digester may be so constructed as to form a beating
chamber about its lower end. The said digester is supported on brackets
with a pit beneath it, into which a vessel can be introduced to catch
the refuse. The said heating chamber communicates with a furnace
through a flue in which a damper is placed to regulate the flow of heat
to the digester. This digester is fitted at its upper end with a man-hole
and plate, and at its lower end with a similar hole and plate, the matter

page_text: to be rendered being introduced through the upper hole and the refuse-
to be drawn out through the lower hole. In operating this digester it is
first filled with water up to just above the fire surface. The fat is then
introduced, and the fire lighted in the furnace and continued until
sufficient steam pressure and heat have been generated to completely.
render the fat. In this process it will be seen that the steam for.
rendering the fat is generated in the digester, not from the constitutional
water of the fat, but from water put in for that purpose. A receiver is
arranged over the furnace in masonry so constructed as to form a
chamber around its lower end communicating with the furnace through,
a flue, over which a damper is placed to regulate the admission of heat:
to the said chamber, which is also in communication with the chamber
and chimney by means of another flue. The said receiver is made to
communicate with the digester by means of a pipe fitted with a cock,
by which the communication may be opened or closed, and the upper
end of the said receiver is also in steam communication with the upper.
end of the digester through pipes fitted with cocks to regulate the
admission of steam. The object of this receiver is to take the fat slowly
out of the digester as fast as it is rendered, the upper and lower com-.
munications between the two vessels establishing an equilibrium of
pressure in the receiver, leaving the fat to enter it with a velocity due to
its gravity merely, whatever the pressure may be in the digester. It is
also for the purpose of treating it in under a vacuum if necessary to:
purify, medicate, and cool it. I first draw off the water of condensation
and other foreign matter, and then apply a gentle heat thereto to drive.
off the vapor and gases remaining in the fat. The heat may be applied
to the bottom of the receiver through the flue, or it may be applied to
the inside of the receiver through the agency of steam by means of a
coil of pipe. Before the heat is applied to the receiver a vacuum may:
be created in it by applying a receiving pipe to the cock, through which
the air can be exhausted, in which case the gases and vapors will go
off at a very low temperature, and the perfuming gas or vapors can be
readily introduced. This digester is also fitted with an automatic
drawing off pipe provided with a foraminous nozzle and float to follow
the rise and fall of the fat as in the tank first described. But in this
case the fat is delivered through a pipe into a reservoir, in the bottom
of which a coil of pipe is placed, to one of whose ends a pipe' is con-
nected from the top of the digester, and to whose other end a pipe is
connected leading to the bottom of the digester, by means of which

page_text: pipes I can throw a current of hot steam in the said coil and return
the condensed water therefrom to the digester. The object of this
reservoir fitted with a coil of pipe as aforesaid is to drive off the offensive
gases and vapors into a condenser, out of which it flows into a chamber
filled with some deodorizing material such as charcoal and chloride of
lime, whence it is drawn through the pipe into the gutter or sewer.
In addition to the pipes above described to carry the offensive gases and
vapors from the purifying receivers to the condenser and deodorizer or
either. of them there is a pipe leading directly from the digester to the
condenser to dispose of the gases as before described and there is also
a pipe leading from the top of the digester to a coil of perforated pipe
set in the wall of the furnace to deliver these gases and vapors into the
fire for consumption. To effectually consume these gases and vapors how-
ever, as they are forced out of the digester by the pressure of the steam,
it is necessary to prepare them on their way to the fire by thoroughly
Buperheating them and by uniting with them a current of fresh air as
they enter the furnace. To accomplish this purpose I combine with the
tank or digester a superheating and consuming furnace of peculiar con-
struction which constitutes the third part of my Invention. The inside
or lining of this furnace is composed of four semicircular plates, around
the outside of two of which the other two plates are fitted and arranged
to form an open space. These inside plates are formed with a series of
nipples on their inside surface, and the outside plates are fitted with a
series of tubes corresponding in number to the nipples in which their
inside ends are adjusted. The said tubes are screwed into the outside
plates. They reach back to the pipe or flue leading from the digester,
and are so formed as to leave a flue or passage way between them and
the inside of the nipple. These furnace plates are set in brickwork
over grate bars and an ash-pit, the said brickwork being carried up
above the furnace to form a deep cylindrical chamber, in which a coil
of pipe is arranged, the upper end whereof leads to the digester and the
lower end whereof leads to the space between the furnace plates in
which the gas and steam from the digester are delivered, and whence
they escape into the fire through the nipple around the tube with a
velocity due to the pressure in the digester, a current of air being created
and carried into the furnace through the tube out of the flue along
with the gas and steam. This flue is formed in the brickwork all the
way up around the chamber over the furnace to heat the air before it
is drawn into the furnace, and to take the heat back to the furnace and

page_text: keep the outside wall thereof from becoming hot. From the coil of
pipe there is a small branch pipe leading to the ash-pit, by which a
stream of steam and gas can be thrown under the grate bars and by
which the draft of the furnace can be increased. The fumes and smoke
of the furnace are of course carried off through the smoke pipe into the
main chimney.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 26th February 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," No. 8, South-
ampton Buildings, London, Consulting Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of August, in the.
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did, for Herself, Her heirs and successors,.
give and grant unto me, the said William Robert Lake, Her special
licence that I, the said William Robert Lake, my executors, adminis-
trators, and assigns, or such others as I, the said William Robert,
Lake, my executors, administrators, and assigns, should at any time.
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"AN IMPROVED METHOD OF AND APPARATUS FOR RENDERING AND REFINING LARD,
TAILOW, AND OTHER FATTY AND OLEAGINOUS MATTER," a communication. to. me
from abroad by Charles James Everett, of Highwood Park, New Jersey,
United States of America, upon the condition (amongst others). that I,
the said William Robert Lake, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and.
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
ソ

page_text: NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification:-
The Invention which I have reduced to practice consists of various
parts, and will best be understood by a detailed description of the
different forms of apparatus in which it is embodied.
. In the Drawing making part of this Specification the different parts
of said Invention are illustrated, and to give a clear understanding of
their nature and operation I will proceed to describe them seriatum.
Figure 1 illustrates a vertical section of two parts of my Invention,
the one part being a new style of tank for rendering, and the other a
furnace fitted to destroy the offensive gases and vapors developed in.
the process. The digester in which the fat is melted is represented
by A. It is a close vessel made of boiler iron heavy enough to resist a
pressure of at least fifty pounds per square inch, and is fitted with flues
B, B, as many as may be useful to provide what heating surface may be
necessary to insure a rapid reduction of the fat. From three to four of
these flues six inches in diameter will be found sufficient in a digester
of the capacity of ten thousand pounds. This digester is entirely
enveloped in a tight iron vessel or jacket F, which for the purpose
of this Specification and description I will style a retort. This retort
is in form the same as the digester, but is larger than the latter
in each dimension by about twelve inches, and is arranged in relation
to it so as to leave a space between the two vessels of from six to
eight inches wide, the two vessels being thoroughly stayed to each
other, as shown by the Drawing. This retort and digester when united
as above described make a double vessel, which for the purpose of this
description I will call the tank. In the upper end of this tank a man-
hole C is made through which the fat is introduced into the digester,
and which is provided with a steam-tight cover and fitted with the
necessary mountings to secure it against the pressure maintained in the
digester, and in the side near the bottom of said tank a similar hole D
is made similarly covered and mounted, through which the refuse is
removed after the rendering is completed. This tank after being con-
structed in manner and form substantially as aforesaid is set and
covered in brickwork over a furnace and supported by suitable

page_text: bearing pieces Y in the manner shown. The whole bottom of the tank is
exposed to the action of the fire, and the flues leading from the furnace
to the chimney represented by G rise in a spiral direction around the
tank as high as may be necessary to abstract the heat from the products
of the furnace. The chimney is not shown in the Drawing, but it is of
the ordinary construction, and therefore needs no further description
here. In the inside of the digester there is fitted a pipe V, the upper
end whereof terminates in a hollow socket joint, by which it is connected
to the delivery pipe T, and by which the lower end thereof is left free
to rise and fall on the arc, represented by a dotted line in red. The
lower end of this pipe is fitted with a float H and a foraminous nozzle,
as shown; the float keeps the nozzle near the surface of the melted fat,
and of course rises and falls with it. By means of this pipe the melted
fat, if desired is drawn out of the digester as fast as it is rendered by the
pressure of the steam upon its surface, the pipe T being fitted with a
cock, not shown in the Drawing, by which the flow of the fat is regu-
lated. In addition to the stays by which the digester and retort are
united and braced the retort is still further secured by means of long
stay bolts passed through the flues and fastened to the top and bottom
of the retort, substantially in the manner shown in the Drawing. After
this tank has been constructed and set as above set forth the digester is
charged with fat, and the retort is filled about one-third full of water.
The fire is then started in the furnace and the process of melting com-
mences, the licat being transmitted from the furnace to the material in
the digester through the water and steam in the retort. Both the
digester and retort are fitted with a steam gauge to indicate the pressure
in the respective vessels, which must be high enough to yield the
necessary temperature to insure as rapid a reduction of the material as
may be consistent with a due regard to the safety of the apparatus and
the quality of the melted fat. In treating offal I put a little water on it,
but usually there is no water put in the digester save what is contained
in the fat itself, which will vary in different kinds of fat from ten to
twenty per cent. of its weight, so that instead of throwing steam into
the digester from. a separate boiler, the pressure therein is generated from
the constitutional water in the fat, avoiding by the use of the retort at
once the. necessity of a separate boiler, the possibility of burning the fat,
and the condensation of steam in the digester, which it will be seen is
entirely.enveloped in a sheet of hot steam and water. This completes,
a description of the first. part.of my Invention.

page_text: The second part thereof is embodied in another form, and is shown in
the Drawing by Figure 2. In this Drawing A represents a tank or
digester set in masonry so constructed as to form a heating chamber
about its lower end. Said digester is supported on brackets B and a
plate B', so arranged as to leave a pit beneath it into which a vessel can be
introduced to catch the refuse drawn from the digester. Said heating
chamber communicates with a furnace D through the flue E, in which
a damper F is placed to stop or regulate the flow of heat to the digester:
From the top of said heating chamber there is a chimney or flue G, by
which the draft is maintained and the heat drawn back around the lower
end of the digester. This digester is fitted at its upper end with a man-
hole and plate a and at its lower end with a similar hole and plate b,
the matter to be rendered being introduced through the hole a, and
the refuse to be drawn out through the hole b. The above concludes
a description of the rendering tank proper without any attachments
whatever for drawing off or refining the rendered grease.
In operating this digester it is first filled with water up to just above
the fire surface. The fat is then introduced and the fire started in the
furnace and continued until sufficient steam pressure and heat have
been generated to completely render the fat. In this process it will be
seen that the steam for rendering the fat is generated in the digester
containing it not from the constitutional water of the fat, but from water
put in for that purpose, thus avoiding the burning to which the fat is
liable in the fire process, and the expensive apparatus which has hitherto
been employed in steam rendering is also dispensed with. At the same
time a gradual and effectual rendering is obtained as well as a good quality
of rendered fat in at least as short a time as by any other method. In
the Drawing H represents a receiver arranged over the furnace in masonry
so constructed as to form a chamber around its lower end communicating
with the furnace through the flue e, over which a damper f is placed,
to regulate the admission of heat to said chamber, which is also in com-
munication with the chamber C and chimney G by means of the flue h..
Said receiver is made to communicate with the digester by means of a
pipe fitted with a cock J, by which said communication may be opened
or closed. The upper end of said receiver is also in steam communication.
with the upper end of the digester through the pipe k and the branch 1,
both of which are fitted with cocks to regulate the admission of steam.
from one vessel to the other. The object of this receiver is to take the fat;

page_text: slowly out of the digester as fast as rendered, the upper and lower com-
munications between the two vessels establishing an equilibrium of
pressure in the receiver leaving the fat to enter it with a velocity due to
its gravity merely, whatever the pressure may be in the digester. The
object of this receiver however is not merely to receive the melted fat,
but it is also for the purpose of treating it in under a vacuum, if
necessary to purify, medicate, and cool it. This object I accomplish by
first drawing off the water of condensation and such other foreign matter
as may precipitate itself in the bottom of the vessel, and by then applying
a gentle heat thereto to drive off the vapor and gases remaining in the
fat. The heat necessary to accomplish this purpose may be applied to
the bottom of the receiver from the furnace through the flue e, or it may
be applied to the inside of the receiver through the agency of steam by
means of the coil of pipe n. But before the heat is applied to the
receiver a vacuum may be created in it by applying a receiving pipe to
the cock m, through which the air can be exhausted, in which case
the gases and vapors will go off at a very low temperature, and the
perfuming gas or vapor can be readily introduced. This digester is also
fitted with the automatic drawing off pipe, shown by u, provided with a
foraminous nozzle w and float to follow the rise and fall of the fat, the
same as in the tank above described, but in this case the fat is delivered
through a pipe t into a reservoir I, in the bottom of which a coil of pipe x
is placed, to one end of which the pipe z is connected from the top of the
digester, and to the other end of which a pipe y is connected leading to
the bottom of the digester, by means of which pipes I can throw a
current of hot steam in said coil from the top of the digester and return
the condensed water therefrom to the digester. Now the object of this
reservoir fitted with a coil of pipe as aforesaid is to drive off the offensive
gases and vapors through the pipe j into a surface or jet condenser N
(the Drawing shows a surface condenser), out of which it flows through
the pipe P into the deodorizing chamber R, Q, filled with some deo-
dorizing material, such as charcoal and chloride of lime, from whence it
In addition to
is drawn through the pipe T into the gutter or sewer.
the pipes above described to carry the offensive gases and vapors from
the purifying receivers to the condenser and deodorizer, or either of
them, there is also a pipe L leading directly from the digester to the
condenser to dispose of these gases as before described, and there is also
a pipe K leading from the top of the digester to a coil of perforated

page_text: pipe M set in the wall of the furnace to deliver these gases and vapors
into the fire for consumption. To effectually consume these gases and
vapors however as they are forced out of the digester by the pressure of
the steam it is necessary to prepare them on their way to the fire by
thoroughly superheating them and by uniting with them a current of
fresh air as they enter the furnace. To accomplish this purpose I
combine with the tank or digester a superheating and consuming
furnace of peculiar construction, which constitutes the third part of my
Invention. The inside or lining of the furnace is composed of four semi-
circular plates, of which the two inside ones are shown by O, P, around
the outside of which the other two plates are fitted and arranged to
form an open space 6 in the manner shown. These inside plates are
formed with a series of nipples on their inside surface, as shown by P,
and the outside plates are fitted with a series of tubes corresponding in
number to the nipples in which their inside ends are adjusted. The
said tubes are screwed into the outside plates; they reach back to the
flue L, and are so formed as to leave a flue or passage way between them
and the inside of the nipple, as shown by v. These furnace plates so
made and fitted are set in brickwork over grate bars and an ash-pit M in
the manner shown, said brickwork being carried up above the furnace
to form a deep cylindrical chamber, in which a single, a double, or a
triple coil of pipe K is arranged, the upper end I whereof leads to the
digester, and the lower end of whereof leads to the space between the
furnace plates in which the gas and steam from the digester are delivered,
and from whence they escape into the fire through the nipple P around
the tube a with a velocity due to the pressure in the digester, by which a
current of air is created and carried into the furnace through the tube a
out of the flue L along with the gas and steam. This flue L is formed
in the brickwork all the way up around the chamber over the furnace
for the purpose of heating the air before it is drawn into the furnace, and
for the purpose of taking the heat back to the furnace and keeping the
outside wall of the furnace from getting hot to the discomfort of the
attendant. From the coil of pipe K there is a small branch pipe Q
leading to the ash-pit M, by which a stream of steam and gas can be
thrown under the grate bars and by which the draft of the furnace can be
increased in case of need. The fumes and smoke of the furnace are of
course carried off through the smoke pipe N into the main chimney of
the works.

page_text: Having now described the different parts of said Invention, and the
manner in which they are applied to use, the features herein which are
deemed to be new and which I claim as said Invention are,-
First. Making a close water jacket or retort in combination with the
digester and a part of it, and arranging said water jacket so made a part
of said digester in direct communication with the furnace, making the
water jacket to intervene between the fire and the digester, and act as a
means for conveying and distributing the heat from the fire around and
through the substance contained in the digester.
Second. Using the steam pressure generated in a close digester from
the constitutional water of the fat for the purpose of aiding and controlling
the escape of the offensive gases, either to a superheater for consumption
in the furnace or to a deodorizer for the purpose of deodorizing them
in the manner substantially as described.
Third. Avoiding the offensiveness of the gas and steam from a
rendering digester by passing them through a pipe or flue into a con-
denser for the purpose of condensing the vapor, and absorbing in the
water of condensation the offensive gases, and by then passing said
water of condensation through a deodorizing chamber filled with charcoal
and chloride of lime or other suitable deodorizing material, substantially
as described.
Fourth. Rendering fatty matter under steam pressure generated in the
digester containing it by the direct application of heat thereto.
Fifth. The combination of a receiver with a steam generating digester
so arranged in connection with said digester as to receive the melted fat
therefrom, and so that the heat of the furnace used to generate the steam
can also be used for the purpose of purifying the rendered fat, substantially
as described.
Sixth. Refining and purifying the rendered fat in a reservoir arranged
in connection with the digester, and fitted with a coil of pipe so arranged
in said reservoir and connected to said digester as to receive the steam
therefrom and return the condensed water thereto, substantially in the
manner described.
Seventh. Deodorizing the offensive gases driven off in rendering or
refining animal matter by passing them through a deodorizing chamber

page_text: described.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Twenty-sixth day of February,
in the year of our Lord One thousand eight hundred and seventy.
WILLIAM ROBERT LAKE. (L.S.)
Witness,
H. J. GEDGE,
Clerk to Haseltine, Lake, & Co.