Improvements in the Process of Refining and Improving Butter, Lard, Oils, and other Fatty Matters.
Year: 1894

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883) as allowed by
the decision of the Chief Examiner of the 21st day of September 1898.
Date of Application, 7th Aug., 1894-Accepted, 9th Feb., 1895
COMPLETE SPECIFICATION (AMENDED).
Improvements in the Process of Refining and Improving Butter,
Lard, Oils, and other Fatty Matters.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the County
of London, Patent Agent, do hereby declare the nature of this invention, a com-
munication to me from Joseph Henderson Campbell, Chemist, and Charles
Henderson Campbell, Engineer, both of the City, County, and State of New
York, in the United States of America, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
The object of this invention is a process for treating oils, fats and other fatty
matters and more especially such materials as butter or lard, which, either by reason
of improper methods of manufacture or from exposure, have become deteriorated, to
the end that the same may be rendered permanently sweet and wholesome, and the
process herein described more particularly relates to the treatment of impure or
rancid butter, to the end that a pure butter-oil may be extracted therefrom, to which
may be restored a true butter favour, as will be hereinafter explained.
So far as I am aware, the deleterious elements in such impure butter oils, fats etc.,
are of an albuenoid nature and furnish support for living organisms which render
the materials spoken of unhealthy and dangerous as articles of food.
To remove therefrom these albumenoid substances in an expeditious, cleanly and
complete manner, without the use of chemicals, is the particular aim of the present
process.
I will aided by the accompanying drawings describe the process in connection
with the treatment of impure butter for the purpose of converting the saine into pure
and wholesome butter, it being understood that similar treatment is applicable to
other impure fats, oils, etc. to render then pure.
Should the material to be treated be found to contain a quantity of objectionable
solid matter such as salt, said material is melted by heat suitably applied, and such
solid or semi-solid materials as rise to the surface may be skimmed off, while the
remainder may be removed by allowing them to precipitate to the bottom of the
vessel in which the treatment is applied, drawing them off therefrom; or a quantity
of water equal in weight to about one-fourth the weight of the contents of the vessel
may be introduced on top of the melted contents of the vessel and allowed to settle
therethrough to the bottom, whereby it will be found that the solid and semi-solid
impurities will be carried down to the bottom of the vessel and may be drawn off
therefrom.

page_text: After such solid and semi-solid impurities have been removed as far as possible by
either of the methods above set forth, although the showering of water is preferred as
being the most rapid and efficient method, the contents of the vessel may be treated
in either one of two ways to remove therefrom the albumenoid substances.
The first method is by the application of an air blast produced by a Root or other
power blower, whereby moisture will be carried off, and the albumenoid substances,
which while moisture is mingled therewith are of a somewhat mucilaginous nature,
are converted by the deprivation of moisture into solid substances. These solid
albumenoid substances may be removed by showering in the manner above described,
or by fitration. If the material undergoing treatment has not been completely
deprived of its solid, semi-solid and albumenoid impurities by following the steps
above enumerated, repetitions of the air blast and water washing or filtering may be
alternately followed until the desired purity is obtained, which may be determined by
removing a sample and testing the same for odour and flavour. It will be understood
that the above steps are all carried on while the material undergoing treatment is
maintained in a liquid state by heat.
Another method of removing the objectionable albumenoid substances is by the aid
of a vacuum maintained in the vessel containing the material undergoing treatment
while such material is in a melted state. It is found that a vacuum represented by
26 inches on an ordinary vacuum gauge will answer the purpose, while the material
is maintained at a temperature below that necessary to boil water under ordinary
atmospheric pressure. By employing a vacuum as just described, I am enabled to
reduce the temperature of the melted material undergoing treatment and thereby
avoid risk of driving off valuable volatile acids or converting the oils undergoing
treatment into free fatty acids.
In connection with this vacuum treatment, I also, as a step of the process, aërate
the contents of the vessel while still maintaining the vacuum. This aeration, because
of the vacuum existing in the vessel, does not require a power blower for its production,
it being sufficient to allow the air to enter at atmospheric pressure into the vacuum
to produce the effect of an air blast.
The water washing may be applied also to the material undergoing treatment to
precipitate the solid impurities after the vacuum and air blast steps have been per-
formed, or such impurities may be removed by precipitation or filtration without the
aid of water. Of course this latter step of removing the solid impurities by washing,
precipitation or filtration will be carrried on at ordinary atmospheric pressure without
the vacuum or air blast being maintained.
The manner of converting the purified butter-oil into butter after the above treat-
ment will be hereinafter more fully explained.
Referring to the drawing of which there is but a single figure, A represents the
vessel in which the materials are treated. B represents a jacket around the same,
into which at b6 may be admitted a heating medium, either hot water, steam or other
heating medium, which finds its exit at 4, whereby a constant circulation is kept up
in the jacket. A cover C, shown open in full lines in the drawing, is adapted to
hermetically seal the top of the vessel A. At the bottom of the vessel A is an cutlet
D through which the contents of said vessel may be drawn off, said outlet being
connected with a swiveling pipe E which is shown with its nozzle above the refuse
tank and when in that position adapted to draw off the salt, curd, water, etc.
precipitated or washed to the bottom of the vessel A. The outlet pipe D is controlled,
as shown, by a suitable valve G. H diagrammatically represents a vacuum pump of
any suitable construction, h a pipe leading therefrom to the top of the vessel A, h¹ a
vacuum or pressure gauge connected with said pipe h, and h² a cock in said pipe h.
1, diagrammatically represents a power blower of any suitable construction, i the pipe
leading therefrom to the bottom of the vessel A, where it is provided with a per-
forated diaphragm i¹.
Pipe has interposed therein a suitable cock 2. This pipe i is connected with the
atmosphere by a pipe 3, so that when the cock in the latter is turned in a certain
direction and the cock 2 is turned so as to shut off communication with the air

page_text: blower, air at atmospheric pressure will be admitted to the tank A. J represents an
ice-water tank for use more particularly in conferring a butter flavour on the purified
oils when they are to be used for making butter. K represents a hose for applying
water in showers for the purpose of precipitating the solid and semi-solid impurities
to the bottom of the vessel A so that the same may be drawn off.
The operation is as follows: The material to be treated may first be somewhat
purified by simply reducing the same to a melted state and then skimming
off such impurities as rise to the top, allowing the other impurities to
settle to the bottom and drawing them off through the outlet D and swivel
pipe E into the refuse tank F. This operation may be facilitated by showering
with water in quantity equal to about one fourth by weight of the contents of the
vessel A, whereby solid and semi-solid impurities are washed, as it were, to the
bottom of the vessel, to be drawn off. The next step, or the first step if the step
just described is not found necessary, is to deprive the albumenoid substances of
moisture. This may be done with the certainty of not driving off valuable volatile
oils by what I terin the vacuum step. By this step it has been ascertained that the
temperature may be as low as 120° Fahrenheit or even lower, and under a vacuum
of 26 inches the deleterious materials will be largely removed without volatilizing
valuable oils, while at the same time tending to carry off all the moisture, whatever
additional moisture that may be left being carried off by the admission of air at
atmospheric pressure.
In carrying out this vacuum step, the lid C is closed and hermetically sealed, and
the cocks and 2 are both closed. The temperature of the heating medium in the
jacket B should be maintained at about 120° Fahrenheit.
The vacuum pump H is started and its operation continued until the pressure
vacuum gauge h¹ registers 26 inches. The operation of the vacuum pump is continued
until the material undergoing treatment has been deprived of all moisture. This is
determined by stopping the vacuum pump and if the pressure gauge continues to
stand for say ten minutes at 26 inches, it is considered that this step of the process
has been carried sufficiently far.
The cock is then opened whereby the air at atmospheric pressure is admitted to
the pipe 3 and thence to the interior of the vessel A, where it serves to agitate the
contents of the vessel and tends to break up and separate the particles contained
therein, and also divides certain deleterious matter and carries the same off, while at
the same time insuring that the contents of the vessel are entirely deprived of
moisture.
While the air at atmospheric pressure is entering, the vacuum pump is con-
tinuously operated.
The operation of the vacuum pump and the air blast and vacuum pump combined
may be alternated a number of times depending upon the particular oil etc., being
treated. Cocoanut oil, for instance, may require five or six alternate treatments,
while cotton-oil would require but a single alternate treatment.
I ascertain when the process has been carried sufficiently far by removing a sample
and testing according to the ordinary tests for purity.
I may also if found desirable, wash the material after its treatment in the vacuum
and to the air blast, with water, as before described, to filter it.
In such cases where it is found desirable or convenient to depend upon an air blast
without the aid of the vacuum, the contents of the vessel A are heated as before,
although a higher temperature will be found necessary. I then after having removed
certain impurities by, skimming, precipitation and washing as above described, start
the air blower and force an air blast into the contents of the vessel A, it being under-
stood that the cover C is open and that the vacuum pump and its connections are
cut off, also that communication through the pipe with the atmosphere is shut off.
Preferably, the air is dried before its entrance into the vesse! A so as to deprive it of
moisture, whereby it will be enabled to take up any free water that may be mixed
with the butter-oil, and may deprive the mucilaginous substances above referred to
of the moisture therein contained.

page_text: The air blast is continued until the contents of the vessel have been deprived of
moisture, which may be determined by testing. Resort is then had to washing,
filtering or precipitation and skimming in the inanner heretofore described for re-
moval of the solid albumenoid particles.
Should the oil now remaining after the washing etc., be not sufficiently sweet, the
blower is again turned on and air forced through as before, followed again by a
shower.
This operation of aërating and showering may be continued alternately until a
perfectly sweet, pure oil, free from all offensive gases and odours, is obtained, it being
understood that after each showering, the precipitated contents are drawn off before
the next aĕration.
To convert the purified oil contained in either of the ways above described into
butter of the proper flavour, there is added thereto about one half its weight of sweet
milk, previously raising the milk to a temperature of about 90° Fahrenheit. This
operation may be carried on in the vessel A or in a vessel similar to it. The air blast
is then turned on and continued until the oil and milk are thoroughly commingled
and reduced to the consistency of a thick cream; then there is added a weight of
sour milk or buttermilk equal to the weight of milk previously added, the air blast,
however, being continuously in operation.
The amount of sweet milk or buttermilk or sour milk added depends somewhat upon
varying conditions. When the oil is dense, a greater amount of sweet milk may be
added.
If the sour milk is very acid, then a less quantity of that is used and a greater
quantity of sweet milk, the addition of both depending upon the quality of butter to
be produced.
Before adding the cream, milk or sour milk to the butter-oil, the milk etc. is
preferably aerated at a temperature of about 40° Fahrenheit; whereby the flavour
and odour of the milk etc., are improved. When the sweet milk and butter or sour
milk and the butter-oil are all thoroughly commingled, and at about a
temperature of about 120° Fahrenheit, the mixture is discharged into the tank J
. containing ice-water, and therein, by the action of the cold water, it is changed from
a liquid to a solid in the form of minute flocks or crystals in which the sour inilk and
cream will be imprisoned.
These flocks or crystals are now removed from the tank J and placed on drain tables
where they are permitted to remain for about 24 hours, or for a sufficiently long period
of time for the sour cream or buttermilk to impart its flavour to the butter flakes or
crystals.
The material is then placed in a churn that contains preferably about four times its
weight of milk, which it is also preferred to previously, aerate at a temperature below
40° Fahrenheit and which has also previously been churned until the butter is forming
or until the butter is "broken" and the mixture is churned until the crystals have
changed into snail globules the size of a buck-shot, or of the size and appearance of
the particles produced in the ordinary method of churning.
When this occurs the product is removed from the churn and is worked, salted and
otherwise treated as is butter made in the usual way.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. The process of refining and improving butter which consists in treating the same
while in a melted state with an air blast and water alternately, substantially as set
forth.
2. The process of refining and improving butter which consists in treating the same
in a melted state, first removing by precipitation a portion of the impurities thereof,
then adding water on top of the material undergoing treatment and allowing the
same to settle therethrough, removing the said water with its collected impurities,
and subsequently treating to an air blast, substantially as set forth.

page_text: 3. The process of refining and improving butter which consists in alternately
treating the same to water and an air blast, then adding sweet milk to the purified
butter-oil in the presence of an air blast until the mixture is of about the consistency
of cream, then adding butter or sour milk without interrupting the air blast,
drawing the contents off into an ice tank, removing the flocculent particles
thereby formed, and subsequently churning the same in the presence of sweet milk
or cream, substantially as set forth.
4. The process of refining and improving butter, which consists in alternately
treating the same to water and an air blast, then adding sweet milk to the purified
butter-oil in the presence of an air blast until the mixture is of about the consistency
of cream, then adding butter or sour milk without interrupting the air blast,
drawing off the contents into an ice tank, then removing the flocculent
particles thereby formed, and churning the same in the presence of milk or
cream which has been already partially churned, substantially as set forth.
B. J. B. MILLS,
By Harris & Mills,
23, Southampton Buildings, London, Agents.