An Improved Process for the Purification of Brine.
Year: 1892

page_text: Date of Application, 8th Mar., 1892-Accepted, 9th Apr.. 1892
COMPLETE SPECIFICATION.
An Improved Process for the Purification of Brine.
1. CALEB GROZIER COLLINS, Electrical Engineer of Woodsburgh, Kings
County, State of New York, United States of America, 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. :-
My present invention is an improvement upon the process of purifying brine set
forth in my United States Patent No. 459,236, of September 8th, 1891. in which
the brine is subjected to a current of electricity having an electromotive force not
exceeding 2 volts in intensity, or insufficient to decompose the chloride of sodium..
The purification of the brine by electrolysis as above set forth is due to the
decomposition of the impurities by the electric current thereby rendering them
insoluble and, also to the formation of ozone by the decomposition of water, the
oxidizing and consequent purifying action of which is well known.
As however in the case referred to, the electric current must first charge the
brine with oxygen before any considerable amount of ozone can be produced, since
the formation of the ozone is dependent upon the presence of free oxygen in the
brine upon which the ascent oxygen liberated by the electric current reacts to
convert it into ozone, it is obvious that the process is comparatively slow in so far
as the purification depends upon the ozone present.
My present invention consists in the introduction of an independent supply of
oxygen into the brine, in conjunction with the use of an electric current of an
electro-motive force not exceeding 2 volts in intensity, so that the nascent oxygen
generated in the brine by the current will combine immediately with the dissolved
oxygen, producing thereby a maximum amount of ozone under conditions most
favorable for the purification of the brine without decomposing the chloride of
sodium.
My invention also includes incidentally the continuous process of purifying brine
by treating it simultaneously with free oxygen and an electric current having an
electro-motive force not exceeding 2 volts in intensity, and removing the precipitates
thus formed by mechanical means.
In the accompanying drawing, I illustrate symbolically apparatus suitable for
carrying out my improved process of purifying brine, although I do not confine
myself to the use of any special construction and arrangement of parts since it is
obvious that the apparatus may be varied or modified materially and still be
adapted to meet the practical and essential requirements of my invention.
The drawing shows a tank A, divided into two compartments B and C, by the
vertical partition (<.
In the first compartment B. are arranged a series of anodes b, and cathodes 4,
connected with the respective poles of a battery D, or other suitable source of
electricity, care being taken to limit the current to an intensity not exceeding
2 volts so as to protect the chloride of sodium from decomposition. The
electrodes,, are of carbon, platinum or other material not prejudicially acted
upon by oxygen or by the impurities contained in the brine to be treated.
A supply pipe E, is arranged above the electrodes b, b, and is preferably formed
with a series of discharge openings e, arranged to distribute the supply of brine
uniformly to the tank. A valve e', controls the supply of brine. Any suitable
number of these supply pipes E, may be employed in effecting the desired result,
according to the requirements and capacity of the apparatus used.
Below the electrodes b, b, is situated an oxygen distributing pipe 0, perforated
or otherwise formed to permit of the introduction of the oxygen gas into the
surrounding brine.

page_text: The oxygen pipe O, provided with a valve o, is connected with a reservoir of
compressed oxygen, or with any other suitable or convenient source of supply.
The oxygen escaping from the pipe O, combines with the nascent oxygen from
the electrodes to form ozone, which acts upon impurities held in solution or in
suspension in the brine, precipitating or destroying them.
The bottom of the tank B, is provided with discharge pipes F, through which
solid precipitates settling to the bottom may be removed, and with a brine dis-
charge pipe G, arranged at a suitable level, through which the brine clarified by
the combined action of the electric current and the ozone may be withdrawn.
.Both the discharge pipes F, and G, are provided with valves f, and g.
respectively.
There is an opening a', in the partition a, of the tank A, which opening
establishes communication between the two compartments B, and C. In the
compartment C, above the opening a', is situated a horizontal partition or floor c,
formed with a series of perforations through which the brine is enabled to rise
upward into the filtering chamber C₁, provided with a suitable filtering medium c',
preferably having imbedded in it a series of electrodes c2, c³, connected alternately
with the positive and negative poles of the battery D', or other suitable source of
electricity, in such manner that the current may be thrown on or off the filtering
material at pleasure.
The current of electricity is so regulated as not to exceed 2 volts in intensity
under any circumstance, so as to protect the chloride of sodium from decomposition.
The filtering chamber C, is provided with an outlet or overflow pipe e', which is
above the filtering medium, but on a lower level than that of the supply pipe E,
so that the purified brine will flow off naturally by hydrostatic pressure.
In operation the brine to be treated is introduced into the tank B, by the supply
pipe or pipes E. In descending through the said compartment B, it is impregnated
with ozone evolved by the combination of the nascent oxygen generated between,
the electrodes by an electric current of not more than 2 volts, with the oxygen
introduced by the supply pipe O. Most of the impurities are rendered insoluble and
precipitated or are destroyed by the combined action of the electric current and
the ozone.
The insoluble precipitates may be allowed to settle to the bottom of
the compartment B, to be eventually removed through the discharge pipes F, or by
other means, while the purified brine may be conducted off by the discharge pipe G,
or the impurities may be positively separated and eliminated from the brine by
causing the latter to flow through the filtering material ', in the second com-
partment C, preparatory to its discharge for evaporation and crystallization.
When the brine is of such a character that the impurities after decomposition
and precipitation in the compartment B, are liable to re-combine to form soluble
compounds when beyond the combined influence of the electrical current, I connect
the anodes and cathodes in the filtering material c', alternately with the poles of a
battery D', or other sources of electricity, care being taken to duly regulate and
maintain the current at an intensity below 24 volts, in which case the soluble com-
pounds, if re-formed as above stated, are again decomposed by the electrical
current into insoluble products which are positively removed by the filtering
material and retained thereby as set forth in my Patent No. 459,236, hereinbefore
referred to.
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:
First. The process of purifying brine herein set forth, consisting in introducing
an independent supply of oxygen into the brine and subjecting the brine to a
current of electricity having an electro-motive force not exceeding two and
one-half volts in intensity, whereby nascent oxygen is liberated and combines
with the oxygen independently introduced into the brine to form ozone, without
decomposing the chloride of sodium substantially in the manner described,

page_text: Secondly. The process of purifying brine herein set forth, consisting in intro-
ducing an independent supply of oxygen into the brine, subjecting the brine to a
current of electricity having an electro-motive force not exceeding two and
one-half volts in intensity, whereby nascent oxygen is liberated and combines
with the oxygen independently introduced into the brine to form ozone without
decomposing the chloride of sodium and then separating the resulting precipitates
from the brine by passing it through a filtering medium substantially in the manner
and for the purpose described.
Thirdly. The process of purifying brine herein set forth, consisting in intro-
ducing an independent supply of oxygen into the brine, subjecting the brine to a
current of electricity having an electro motive force not exceeding two and one-
half volts in intensity, whereby nascent oxygen is liberated and combines with the
oxygen independently introduced into the brine to form ozone, without decomposing
the chloride of sodium, and then separating the precipitates from the brine by
passing it through a filtering medium under the influence of an electric current noi
exceeding two and one-half volts, substantially in the manner and for the purpose
described.
Dated this 7th day of March 1892.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.