IMPROVEMENTS IN APPARATUS FOR FILTERING CHEMICAL SOLUTIONS AND DRYING THE RESULTING PRECIPITATES
Year: 1881

page_text: LETTERS PATENT to Henry Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for an
Invention of "IMPROVEMENTS IN APPARATUS FOR FILTERING CHEMICAL
SOLUTIONS AND DRYING THE RESULTING PRECIPITATES." A communication
from abroad by Denis Monnier, of Paris, in the Republic of France.
PROVISIONAL SPECIFICATION left by the said Henry Edward Newton at
the Office of the Commissioners of Patents on the 28th April 1881.
"
HENRY EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Civil Engineer. "IMPROVEMENTS IN APPARATUS FOR
FILTERING CHEMICAL SOLUTIONS AND DRYING THE RESULTING PRECIpitates."
LA communication from abroad by Denis Monnier, of Paris, in the Republic of
France.]
The object of this Invention is to provide for use in laboratories and elsewhere
a filtering apparatus with a more extended filtering surface than heretofore, and
means for drying the precipitates, whereby the filtration will be more effectual
and rapid than in the filter of the ordinary form of a funnel, a considerable
economy in the quantity of filtering paper used will be effected, and the precipitates
obtained being spread over the filtering surface in a layer of equal thickness may
be desiccated without removing them from the filtering apparatus.
The filtering apparatus consists of a short cylinder, at the bottom of which is
placed a piece of wire gauze, and the cylinder and gauze are placed in the mouth
of a funnel.
Inside this cylinder is placed a second cylinder, a sheet of filtering paper having
been previously placed across the mouth of the first cylinder.
A filtering apparatus is thereby formed, having a much larger filtering surface
than has hitherto been attainable.

page_text: This apparatus may be employed with any convenient form of receiving vessel,
but it is preferred to fit it to a vessel from which the air can be exhausted, as the
rapidity of the filtration will be thereby increased.,
This latter arrangement is also necessary when it is desired to dry the precipitates
in the filter. The drying operation is effected by means of heated air, which is
drawn into the filter through a tube connected with an inverted funnel or cover
placed over the external cylinder.
This tube is heated by a gas burner of suitable construction, and the air on its
passage through it becomes heated. The tube may be gilded or silvered internally
to prevent any chemical action which may be hurtful to the precipitates.

page_text: .
SPECIFICATION in pursuance of the conditions; of the Letters Patent filed
by the said Henry Edward Newton in the Great Seal Patent Office on
the 27th October 1881.
HENRY EDWARD NEWTON, of the Office. for Patents, 66, Chancery Lane, in the
County of Middlesex, Civil Engineer. IMPROVEMENTS IN APPARATUS FOR
FILTERING CHEMICAL SOLUTIONS AND DRYING THE RESULTING PRECIPITATES."
A communication from abroad by Denis Monnier, of Paris, in the Republic of
France.
The object of this Invention is to provide for use in laboratories and elsewhere
a filtering apparatus having a, more extended filtering surface than heretofore, and
which is intended to replace the old glass or earthenware filtering funnels. By the
use of the improved filtering apparatus the filtration will be much more effectual
and rapid than in the old form of funnel, and a considerable economy in the
amount of filtering paper used will be effected. The Invention also consists.in
adapting to the filtering apparatus means for drying the precipitates. which will
be found spread over the surface of the filtering paper after the filtering operation
in a layer of equal thickness, so that they may be desiccated without removal from
the filtering apparatus.
In the accompanying Drawing, Fig. 1 shows a sectional elevation of the improved
filtering apparatus; Fig. 2 is an elevation of the same applied to a receiving
vessel; and Fig. 3 is a sectional elevation of the same, with the means for drying
the precipitate connected therewith.
A. B. is a cylinder, over the bottom of which is stretched some wire ganze C,
and below the gauze is a funnel D. E.
Inside the cylinder A, B. is placed a second cylinder F, the outer lower edges of
which are rounded and rest, when the cylinder F is in position, on a ring G placed
between the cylinder A, B, and the wire gauze C.
In order to use the filtering apparatus the cylinder F is withdrawn, and a piece
of filtering paper is spread over the top of the cylinder A, B. The cylinder F
then forced down into A, B, taking with it the paper. By this means the paper
is stretched above the gauze C, and should it break the gauze will hold the
precipitate. When filtering the spout E is inserted in the mouth of a flask II.
which is provided with an india rubber cork I.. The solution is then poured into
the filter, and upon creating a vacuum in the flask through, the tube K, either by a
pump or with the mouth, the liquid will be drawn through the paper.
After the filtration the precipitate may be washed as usual, but as the
precipitate is spread in an even layer over the paper, a very slight amount of
washing is required.
To dry the precipitate a metal cone L. L. is placed over the cylinder A. B. This
cone is provided at its apex with a tube M. which is connected with a horizontal
tube N. The upper end of the tube M is closed by a cork through which passes
the tube of a thermometer, the bulb of which enters the cylinder A, B.
The free end of the tube N is heated by a Bunsen or other suitable gas burner
or otherwise, and as the vacuum is maintained in the flask H, the air rushes in by.
the tube N, where it is heated, and passes to the cylinder A, B.
The interior of the tube N is either gilt or silvered to prevent the formation of
oxide of copper, which might detach itself and pass to the precipitate.
The heated air as it enters A. B, is at first cooled by the vaporisation of the water,
but when this vaporisation is finished the temperature in A, B, will be rapidly
raised. The temperature can be maintained or lowered by increasing or diminishing
the suction or the heating flame,

page_text: If desired the joint between the cone L, L, and the cylinder A, B, may be covered
with an india rubber ring.
The filtering apparatus may be made square as well as round, and of any suitable
material, and one of the many advantages to be derived from its use is the large
filtering surface it gives, instead of filtering through the point of the cone, as in
the ordinary filter. There is also less liability of the paper to break, which in the
ordinary filter is always taking place notwithstanding the precaution sometimes
taken of placing a platinum or paper cone under the point of the paper filter.
By the use of this improved filter the process of filtration. can be effected very
rapidly, and when a square or rectangular apparatus is used there is no loss of
paper.
•
The paper will also take the form of a tray, on the bottom of which the
precipitate will be found, and the tray with its contents may be transferred direct
to the scales without fear of losing any of the contained matters.
If it be desired to remove the precipitate without drying, this can be readily
done, as the precipitate will be found in an even layer only in the bottom of the
paper tray, the sides being entirely free.
Having now described this Invention of "Improvements in. Apparatus for
Filtering Chemical Solutions and Drying the Resulting Precipitates," as commu-
nicated to me from abroad, and explained the manner of carrying the same into
effect, .wish it to be understood that under the above in part recited Letters
Patent I claim,―
་
First. The filtering apparatus constructed substantially as herein shown and
described.
Second. The means, substantially as herein shewn and described, for drying the
precipitates which have been deposited in a layer of uniform thickness during
the filtering operation, as set forth.
In witness whereof. I. the said Henry Edward Newton, have hereunto. set
my hand and seal, the Twenty sixth day of October, in the year of our
Lord One thousand eight hundred and eighty one.
II. E. NEWTON. (L.S.)