in Apparatus Employed therein.
Year: 1884

page_text: in Apparatus Employed therein.
I THOMAS BOWEN of the Morriston Tin Plate Works Morriston in the County of
Glamorgan Tin Plate Manufacturer do hereby declare the nature of my invention
for IMPROVEMENTS IN THE PURIFICATION OF TIN AND ITS ALLOYS AND IN APPARATUS
EMPLOYED THEREIN to be as follows:-
The object of the Invention is to effect the purification of tin and its alloys by
the removal of foreign and undesirable matters contained therein in its more crude
condition in order to better fit it for use in the manufacture of tin plates and
particularly as applied to the coating of high class tin plates, to eliminate the
deleterious ingredients that generate black spots and their concomitant evils and
for other purposes.
I effect this purification by filtration of the metal when in its molten state by
the aid of apparatus which consists of an iron or other suitable metallic vessel
constituting a well, in the bottom of which are fixed at convenient intervals a series
of iron or such like metal filters and ou the surface of such filters is deposited a
layer of prepared scruff or impure tin the thickness of which will be regulated at
will according to the degree of fineness required. Immediately above the filters
and subdividing the space occupied by the layer of scruff or impure tin is placed,
longitudinally, a series of iron or such like metal bars the object of which is to
facilitate the removal of the accumulated matter by filtration which had hitherto
been mechanically held in the tin and whilst performing the removal of such
conglomeration or accumulation to prevent the disturbance of and protect the
layer of prepared scruff or impure tin.
Above such divisional bars is placed an iron or suitable plate the object of which
is, by reason of its lesser specific gravity than the tin, to float on the surface and
ease the force of the current which would otherwise be injurious to the filters
when the tin to be filtered is poured into the well. The said iron or other plate
being removable.

page_text: Improvements in the Purification of Tin and its Alloys and
in Apparatus Employed therein.
I THOMAS BOWEN of the Morriston Tin Plate Works Morriston in the County of
Glamorgan Tin Plate Manufacturer, do hereby declare the nature of my invention
for IMPROVEMENTS IN THE PURIFICATION OF TIN AND ITS ALLOYS AND IN APPARATUS
EMPLOYED THEREIN, 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 the Invention is to effect the purification of tin and its alloys by
the removal of foreign and undesirable matters contained therein in its more crude
condition in order to better fit it for use in the manufacture of tin plates and
particularly as applied to the coating of high class tin plates to eliminate the
deleterious ingredients that generate black spots and their concomitant evils and
for other purposes.
In effecting this purification by filtration of the metal when in its molten state as
more particularly described hereafter I do so by the aid of apparatus substantially
as shewn by the accompanying drawings in which Figure 1 shows a section
horizontally on the line x. x of Fig. 2 and Figure 2 a plan view of a filtering
vessel which cousists of an iron or other suitable metallic vessel A constituting a
well or receiver in the bottom of which are fixed at convenient intervals a series
of iron or such like metal filters a and on the surface of such filters is deposited a
layer of prepared scruff or impure tin the thickness of which will be regulated at
will according to the degree of fineness required say to the broken line b.
Immediately above the filters a and sub dividing the space occupied by the layer
of scruff or impure tin is placed, longitudinally, a series of iron or such like metal
bars c the object of which is to facilitate the removal of the accumulated matter by
filtration which had hitherto been mechanically held in the tin and whilst performing
the removal of such conglomeration or accumulation to prevent the disturbance of
and protect the layer of scruff or some of the deposit of a previous working or
impure tin either in course of operation or in shovelling out or otherwise removing
the superfluous scruff.
Above such divisional bars c is placed an iron or suitable plate & the object of
which is, by reason of its lesser specific gravity than the tin, to float on the surface
and ease the force of the ladling or of the current of inflowing molten tin to the
vessel which would otherwise be likely to disturb and injuriously effect the filters
when the tin to be filtered is poured into the well. The said iron or other plate d
being removable is adapted to be taken out to give free access to the contents of the
receiver and to be replaced.
The circles a indicate suitable situations for a series of filters in the bottom of
the vessel A formed of wires wedged therein in a bundle or parallel series and
locked by a wedge piece f the opening being formed inclined to and from the
middle but I have only thought it necessary to indicate in Figure 2 the manner in
which one of these is filled, viz. at (1), the others being supposed to be so filled.
A similar form of vessel which may have wrought iron sides of one eighth of an

page_text: inch in thickness rivitted to a bottom plate provided with filters as described
intended to be sunk into a pot of molten tin, may be employed in the Tin House
pots except one opening say at e which is left open for ingress of molten metal
when the vessel is sunk into a pot full of molten tin and then when fully sunk
therein, this opening is closed by a conical or other suitable plug attached to the
end of an operating rod or handle e¹ as soon as all inflow of metal has ceased and
then the filter chamber is withdrawn from the pot and the molten tin therein filters
through the interstices between the members of the bundle of wires leaving the
granular or other impurities behind above the scruff and wire filters a in the filter
chamber to be removed when in excess as desired from time to time.
To prevent the insertion of so large a mass in a cold state from effecting chilling
or the solidification of the metal in the pot that chamber A is kept heated by
any suitable means and may be conveniently swung over lowered into and again
raised from the pot of molten metal by means of a jib crane travelling purchase or
otherwise as will readily be understood.
The size of holes a which I have employed with great convenience are about one
and a quarter inches wide at the bottom part of the filter box of one inch thickness
the size of the filter box may vary being such as to easily fit the pot of molten
metal into which it is inserted.
The size of the bars c may be half inch round but this may be varied.
In place of round holes square or other shapes may obviously be employed and
in place of filtering by bundles of wires of round section other forms of metal such
as a combination of wires and plates or plates alone wedged up in series may be
used the object being to obtain a series of fine interstices between the members
thereof to retain the coarser particles of the impurities and let pass the pure tin.
Instead of forming holes directly in the bottom the wires or interstitial
surfaces a may be formed in short lengths of tube inserted.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The purification of tin and its alloys when in a molten state by filtration
thereof through a layer of particles of scruff or deposit retained by interstitial
surfaces as set forth.
2. The apparatus for effecting the filtration or purification of molten tin or its
alloys by filtration substantially as and for the purpose set forth.
3. The herein described method of and apparatus for the filtration or purification
of molten tin and its alloys by causing the same to pass through a layer of matter
supported on interstitial surfaces so as to separate the pure metal from granular or
other impurities.
Dated this 25th day of September 1885