Improvements in Bleaching, Sweetening, and Purifying Oils and Fats.
Year: 1893

page_text: Date of Application, 6th Oct., 1893
Complete Specification Left, 5th July, 1894-Accepted, 6th Oc'., 1894
PROVISIONAL SPECIFICATION.
Improvements in Bleaching, Sweetening, and Purifying Oils
and Fats.
We, FRANK BOULTON ASPINALL, 13 Blessington Road, Lee, Electrical
Engineer, RICHARD WILLIAM HOAR, 30 Thomas Street, Burdeth Road,
Limehouse, Oil Mill Manager, and GEORGE HENRY WISE, 12 Junction
Terrace, Hume Street, Hull, Oil Refiner, do hereby declare the nature of this
invention to be as follows:-
In order to purify and to bleach oils and fats of various sorts we make use of
electricity.
This we do by rendering the oils or fats conducting by the addition of an acid or
an alkali according to circumstances and then we pass a current of electricity
through the oils or fats from one electrode to another.
These electrodes may be of carbon or of other material.
In order to brighten oils and fats we submit them to the light of incandescent
electric lamps which we immerse in the oil or fat.
We also submit oil or fat to the discharge of high tension electricity between
metallic points and preferably in the presence of air or gas.
We also purify oils and fats by mixing them with or superposing them upon a
saline or other suitable solution which we then decompose by electrolysis so as to
liberate chlorine or other gas.
Dated this 5th day of October 1893.
FRANK B. ASPINALL.
R. W. HOAR.
GEORGE H. WISE.
COMPLETE SPECIFICATION.
Improvements in Bleaching, Sweetening, and Purifying Oils
and Fats.
We, FRANK BOULTON ASPINALL, 13 Blessington Road, Lee, Electrical
Engineer, RICHARD WILLIAM HOAR, 30 Thomas Street, Burdett Road,
Limehouse, Oil Mill Manager, and GEORGE HENRY WISE, 12 Junction
Terrace, Hume Street, Hull, Oil Refiner, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
In order to purify and to bleach oils and fats of various sorts we make use of
electricity. This we do by rendering the oils or fats conducting and then we pass
a current of electricity through them from one electrode to the other.
We proceed as follows:- We will suppose that cotton seed oil or olive oil is to
be treated. We prepare a vat or tank with a partition dividing it into two parts.
In each part of the vat or tank we place an electrode; on the positive side we
preferably have a carbon electrode and on the negative side a copper electrode.
The electrodes are connected with a dynamo generating a continuous current and a
pressure not less than six volts is maintained. The carbon electrode on the positive
side is immersed in a solution of common salt of a density about 8 degrees Twaddle.
We render the oil conducting preferably by mixing it with an equal quantity of
salt solution of like strength and with this mixture of oil and salt solution we fill
the part of the tank in which the copper electrode is contained. The partition is

page_text: porous it allows the dynamo current to pass but retains the oil in the part of the
tank in which it is placed.
The oil is kept from separating from the salt solution by constant and vigorous
agitation which is best performed by means of a mechanically driven paddle.
The passage of the electric current generates caustic alkali and hydrogen and
these operate upon the oil whilst the same is also intimately mixed with salt
solution. It results that the impurities of the oil rapidly pass from the oil into the
salt solution. Samples are drawn from time to time and when the operation is
judged to be complete the oil is drawn off and allowed to separate. Or the dirty
salt water may be drawn off and replaced by clean from time to time.
It is usually
advisable not to use heat but when the oil is difficult to purify it may be warmed
but a temperature of 180° Fahrenheit should not be exceeded. By this method oil
is purified with much less loss than by the methods at present in use.
At the same time that the oil is purified chlorine is liberated which may be used
for bleaching.
In some cases in place of employing salt solution we make use of water rendered
strongly acid by the addition of sulphuric acid, we proceed by electrolysis whilst
mixture is maintained by electrolysis as already described.
Sometimes we further purify the oil by washing it with a solution of caustic soda
at a temperature of about 160 degrees Fahrenheit.
Another way in which we sometimes further purify the oil is by treating it in all
respects as in the original purification by electrolysis with salt water except that
it is placed in the compartment of the tank which contains the carbon electrode.
Chlorine is then liberated by electrolysis in intimate contact with the oil and
bleaching is rapidly accomplished and this without any injury to the oil as the
pitchy impurities have been separated by the previous treatment. This method
yields a bleached oil which is suitable for soap making but not for culinary use.
Another method of purifying, bleaching, and sweetening oils is by the production
of a high tension electric discharge in their midst. We employ metallic electrodes
immersed in the oil and produce an arc between the electrodes for which purpose a
very high electric pressure, preferably alternating, will be needed. We prefer to
mingle with the oil a small quantity of solution containing both caustic soda and
common salt and this we keep intimately mixed with the oil by means of air jets.
Before submitting the oil to the electric discharge as above described the pitchy
impurities if in appreciable quantity should be separated by the means previously
described or by some other means.
Another method of brightening oils which by previous treatment have been
rendered comparatively pure is by means of the light from incandescent lamps
immersed in the oil.
For this purpose we provide a vat say three feet deep and on the bottom of the
vat we arrange the electric lamps say one sixteen candle lamp for every square
foot of surface. We fill the vat with oil and light up the lamps.
When the temperature of the oil has risen to 160° to 180° Fahrenheit the
temperature is maintained till the brightening of the oil is complete. In some
cases it is advisable to heat the oil by electric currents applied by resistances or
other well known means and then chill by adding water, doing this two or more
times.
Although our invention is especially applicable to the treatment of cotton oil
and olive oil, it is also applicable with advantage to many others as for example,
rape, cocoanut, African ground nut, Marseilles nut, castor and other vegetable oils
and fats.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The treatment of oils and fats by means of electricity applied to produce

page_text: 2. The treatment of oils and fats by means of a high tension electric discharge
produced in the midst thereof substantially in the manner described.
3. The treatment of oils and fats by means of the light and heat generated by
incandescent lamps immersed in the oil or fat substantially in the
described.
Dated this 5th day of Jule 1801
manner
FRANK B. ASPINALL.
GEORGE H. WISE.
R. W. HOAR.