AN IMPROVED METHOD OF AND APPA- BATUS 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. S, Southampton Buildings, London, Consulting
Engineer, for the Invention of "AN IMPROVED METHOD OF AND APPA-
BATUS 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.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 28th June 1869.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
5 No. 8, Southampton Buildings, London, Consulting Engineer, do hereby
declare, the nature of the said Invention for "AN IMPROVED METHOD OF AND

page_text: 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
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 fora-
minous 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 tho retort is filled about one-third
full of water. The firo is then lighted in the furnace. Both digester
and retort are fitted with a steam gange 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 heating

page_text: chamber about its lower end. The said digester is supported on brackets
with a pit bencath it into which a vessel can be introduced to catch the
refuse. The said heating chamber communicates with a furnace through
a fluc 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 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 suf-
ficient 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 fluc. The said receiver is made to communicate with
the digester by means of a pipe fitted with a cock by which the coni-
munication 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 communications
between the two vessels establishing an equilibrium of pressure in tho
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,. medi-.
cate, 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 tho
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

page_text: 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 connected 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 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.condensor,
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 condensor 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 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 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

page_text: whereof leads to the digester, and the lower ende 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 furnaco
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 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 27th December 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," No. 8, Southampton
Buildings, London, Consulting Engineer, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, hearing date the Twenty-eighth day of June, 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 POR RENDERING AND REFINING LARD,
TALLOW, AND OTHER FATTY AND OLEAGINOUS MATTER," upon the condition

page_text: (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
he performed, and cause the same to be filed in the Great Seal Patent
Oflice within six calendar months next and immediately after the date
of the said Letters Patent.
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:-
This Invention, which as reduced to practice, consists of various parts,
as will be best 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.
Figuro illustrates a vertical section of two parts of my Invention,
the oue 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 suflicient in a digester of the
capacity of ten thousand pounds; this digester is entirely cuveloped 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 inclics, 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

page_text: 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 constructed in manner and form substantially as
aforesaid, is set and covered in brickwork over a furnace a, and sup-
ported by suitable bearing pieces Y in the manner shown. The whole
bottom of the tank is exposed to the action of the fire, and the flucs
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 thic ordinary construction, and therefore needs
no farther 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 are represented by a dotted
line in red. The lower end of this pipe is fitted with a float II and a
foraminous nozzle, as shown, the float keeping 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 regulated. 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 thic
top and bottom of the retort, substantially in the manner shown in the
Drawing. After the 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 commences, the heat being transmitted from the
furnace to the material in the digester through the water and steam in
the retort. Both 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

page_text: 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. 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. This digester
is fitted at its upper end with a man-hole and plate a, and at its lower
end with a similar bole and plate 6, 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 greasc.
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.

page_text: In the Drawing H represents a receiver arranged over the furnace in
masonry, so constructed as to form a chamber around its lower end com-
municating with the furnace through the fluc e, over which a damper f
is placed to regulate the admission of heat to said chamber which is also
in communication 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. And 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 t, both of which are fitted with cocks to regulato
the admission of steam from one vessel to the other. The object of this
receiver is to take the fat slowly out of the digester as fast as rendered,
the upper and lower communications 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 ; 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 gasos 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 the automatic drawing-off pipe shown by u, provided
with a foraminous nozzle wc, and float to follow the risc 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 is connected from
the top of the digester, and to the other end of which a pipe y is con-
nected 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.

page_text: Now thic object of this reservoir fitted with a coil of pipe as aforesaid
is to drive off the offensive gases and vapors through the pipe 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 deodorizing material, such as charcoal and chloride of
lime, from whence it is drawn through the pipe T 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 also a pipe L leading directly from the digester
to the condenser to dispose of the gases as before described, and there
is also a pipe K leading from the top of the digester to a coil of
perforated 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 superlicating them, and by uniting with them a
current of fresh air as they enter the furnace.
1
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 this
furnace is composed of four semicircular 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 b 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 5
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 passageway between them and the inside of the nipple, as shown
by . 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 whereof
leads to the space b between the furnace plates in which the gas and a
stcam from the digester are delivered, and from whence they escarpe
into the fire through the nipple around the tube
with a velocity duc

page_text: 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 arc, of course, carried off through
the smoke pipe N-into the main chimney of the works.
Having now described the different parts of said Invention, as com-
municated to me by my foreign correspondent, 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. Preparing the offensive gases and vapors as they escape from
a rendering apparatus for consumption, by passing them through a
superheater on their way to the firc.
Second. The combination with a rendering digester of a separate
consuming furnace connected thereto for the purpose of consuming the
gas and steam therefrom, as set forth.
Third. The use of a superheater in combination with said consuming
furnace, substantially as shown and described.
Fourth. Consuming the offensive gases and vapors from a rendering
tank apparatus or contrivance by introducing them in, over, or under
the furnace along with an artificial current of hot or cold air induced by
the flow of said steam or gas from the rendering apparatus or super-
heater.
Fifth. I claim the use of jets and blow pipes or tubes applied to
introduce the offensive gases and vapors along with a current of air into,
over, or under the furnace, substantially as shown and described.
Sixth. Making a superheating chamber between the plates composing
the wall of the furnace, substantially as described.

page_text: Seventh. Making the tubes and orifices through which the gas,
steam, and air flow to the furnace a part of the superheater, substantially
as described.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Twenty-seventh day of December,
in the year of our Lord One thousand eight hundred and sixty-
nine.
WILLIAM KO
(..)
Witness,
H. J. GEDGE,
Clerk to Messrs. Ilaseltine, Lake, & Co.,
S, Southampton Buildings,
London.