Improvements in the Manufacture of White Lead and in Apparatus Employed in such Manufacture.
Year: 1890

page_text: Date of Application, 8th Aug., 1890
Complete Specification Left, 8th May 1891-Accepted, 20th June. 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of White Lead and in Apparatus
Employed in such Manufacture.
I, EDWARD VINCENT GARDNER, of Berners College, Oxford Street, in the
County of Middlesex, Professor of Chemistry, do hereby declare the nature of this
invention to be as follows:-
This invention has reference mainly to those processes of manufacturing white
lead in which the vapours or fumes of acetic or nitric acid or a mixture of these
acids are employed to act upon blue lead sheets arranged within a suitable
chamber and to convert them to white lead direct, the said vapour being produced,
preferably, without the chamber, and introduced thereto, by suitable means, and
caused to pass through the chamber and in contact with the plates therein.
It is to be understood that although I prefer to employ either or both of the
acids above specified mixed with vapour of water, carbonic acid gas, and
atmospheric air, this invention is not confined to the use of such gases or vapours
nor to any particular manner of generating or introducing them on the contrary,
it may be employed in processes in which different converting fluids are used and
generated in different manners; however for convenience this invention will be
described as applied to that process of conversion of blue lead to white lead,
wherein the converting fluids used are analogous to those or some of those above
specified.
According to this invention, the blue lead plates are arranged in multiple
parallel series or stories one above another, and closely together, distance pieces
being formed or cast upon them to keep the adjacent plates apart. The converting
fluids are introduced below and distributed equally, and are caused to flow
upwards through the stacks of plates, and be equally and thoroughly distributed.
This thorough and equal distribution is effected by the use of guiding horizontal
diaphragms as hereinafter fully explained.
To expediate the conversion of the blue lead to white lead, 1 subject the plates
to an electrical as well as an acid treatment. This is effected by one method,
by passing a current of electricity through the stacks of plates such
current being produced from without by a dynamo electric generator, or other
source. Or, according to another known method, the electric action may be
obtained by coupling batches of plates with a material such as carbon, tin, and
other metal, which is electro-negative to lead.
The chamber is constructed of side walls and end walls, and a roof the breadth
of the chamber being made relatively short in relation to its length; the effect of
this mode of construction is that it facilitates greatly the filling of the chamber
with plates and removing the material after treatment.
In the side walls, suitable windows are provided, by which the state of the
material under treatment in the chamber can be observed from outside. At each
end and at the front other apertures are provided for the double purpose of
gaining access to the chamber, and to observe the condition of the material under
treatment. The windows are glazed, and are protected and covered in by movable
shutters; that is to say, when the chamber is being filled or discharged, the
shutters and glazed frame are both removed from the apertures whilst merely for
observation, the shutters only of the windows are removed.
The plates are packed closely together, each plate being provided with a
distance piece by which a certain space is allowed between them for the converting
gases. The plates are supported on transverse bearer bars of wood or other

page_text: suitable material, and are separated into batches. According to one example the
batches are separated by the electro-negatives, or electrodes, such negatives
consisting of wooden frames, the space within the frame being filled with coke,
carbon, or other suitable material, the whole being wrapped in cocoanut or coir
yaru matting. These frames are also supported upon bearers, and they also serve
as supports for the superimposed bearers of the stories above the lowermost one ;
thus it will be seen, the lower bearers being first placed in position, the plates
with their electro-negatives intervening, are then stowed or packed and as
the lower story or a part thereof is completed, other bearers are then placed
upon the already laid frames and then again further plates and electro-negative
frames are stowed and packed upon them, and so on, until the whole chamber is
filled.
The effection of equal and proper distribution of the gases and vapours, and the
homogeneous and equal action of gases and vapours upon the plates, is obtained
by providing directing and distributing boards, or partial diaphrams within the
chamber, in horizontal layers.
The gases and vapours are delivered into the chamber by pipes running the
whole length thereof, apertures being provided in these pipes at intervals along
their length, so as to distribute such gases or vapours as equally as possible.
These pipes are disposed within two chambers lined with a suitable flooring. The
gases and vapours in these chambers, will be thoroughly distributed and
will enter the stack of plates practically in equal quantities at all points, and
will therefore rise and How throughout and between and over all the plates.
Then as the gases rise through the series of plates, they pass through the
central space in the first diaphragm; having passed through which they flow
outwards and through the plates in the stories above this diaphragm and then
round the outside edge of a second diaphragm. The effect of these diaphragms is
that no local currents are allowed to take place, and therefore, the gases are
actually caused to be thoroughly and generally distributed. The chamber
although not absolutely a closed one, is practically closed.
The temperature of the chamber should be inaintained at about from 120 to
135 degrees Fahrenheit as at this temperature the best results are obtained.
To keep the chamber at this temperature, it will be obvious the gases or vapours
must be delivered at such a temperature as to effect such result, or of course the
chamber, as the case may be, may be artificially heated or cooled accordingly as,
and if, such gases or vapours are delivered cold or at a temperature exceeding that
such as specified.
The plates and the electro negative material in the frames are coupled by tin or
other suitable strips. These strips are connected to the electrodes and pass over
and in contact with the plates. A loose plate horizontally disposed may be laid
upon the tin strips to keep them in position and in contact with the plates. By
this means it will be seen a ready mode of arranging the plates in electrical
couples is afforded, the action of course being that an electric current is set up
between the electrodes and the plates, by the action of an acid or acids and
watery vapours delivered into the chamber; with the result that the process of
conversion is greatly expediated.
The gases and vapours may be supplied in a vaporous state by any suitable
known means.
In lieu of using the electrodes, a current of electricity, produced from without,
may be passed through the plates, the plates of course being stowed and put into
electrical contact with each other; in such a case, the transverse bearer bars
would have to be supported by suitable bearers equivalent to those afforded by the
frames.
I wish it to be understood that as regards the stowing of the plates, I do not
confine the invention to such stowage particularly as described as their relative
disposition, as regards direction, inay be carried in any other equivalent way to

page_text: the one specified, and the same remark obtains with respect to the supporting bars
and bearers.
It will be evident that the material of which the different parts of the chamber
and its interior fittings are made must be such as will not corrode or be detri-
mentally affected by the gases or vapours, or inimical to the chemical and electrical
actions carried on within the chamber; such things as these are however of course
well understood.
Dated this 7th day of August 1890.
CHEESBROUGH & ROYSTON,
15, Water Street, Liverpool, Applicant's Patent Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of White Lead and in Apparatus
Employed in such Manufacture.
I, EDWARD VINCENT GARDNER, of Berners College, Berners Street,
Middlesex, Professor of Chemistry, 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 :--
This invention has reference, mainly, to those processes of manufacturing white
lead, in which the vapours or fines of acetic or nitric acid, or a mixture of these
acids, are employed to act upon blue lead sheets arranged within a suitable
chamber, and to convert them to white lead, direct, the said vapours being
produced preferably outside the chamber, and introduced thereto, by suitable
means, and caused to pass through the chamber and in contact with the plates
therein.
It is to be understood that although I prefer to employ either or both of the
acids above specified mixed with vapour of water, carbonic acid gas, and
atmospheric air, this invention is not confined to the use of such gases or vapours
nor to any particular manner of generating or introducing them on the contrary,
it may be employed in processes in which different converting fluids are used and
generated in different manners; however for convenience, this invention will be
described as applied to that process of conversion of blue lead to white lead,
wherein the converting fluids used are those, or analogous to those or some of
those above specified.
According to this invention, the blue lead plates are arranged in multiple
parallel series or stories one above another, and closely together, distance
pieces being formed or cast upon them to keep the adjacent plates apart. The
converting Huids are introduced below and distributed equally, and are caused to
flow upwards through the stacks of plates, and be equally and thoroughly
distributed. This thorough and equal distribution is effected by the use of
guiding horizontal diaphragms as hereinafter fully explained.
I
Or
To expedite the conversion of the blue lead to white lead, subject the plates
to an electrical as well as an acid treatment. This is effected by one method, by
passing a current of electricity through the stacks of plates, such current being
produced from without by a dynamo electric generator, or other source.
according to another known method, the electric action may be obtained by
coupling batches of plates with a material such as carbon, tin, and other metal.
which is electro-negative to lead.
The above being the general description of the nature of the process employed
in the practice of my invention, I will now describe it more particularly in and
by the aid of the accompanying drawings which illustrate a chamber and parts used
therein.
Figure 1 is a longitudinal sectional elevation of the chamber.
Figure 2 is an outside elevation of same; and Figure 3 is a cross section of

page_text: igures 4 and are sectional plaus of die chamber, taken at the ITICS A, A,
and B, B, respectively, in Figure 1.
Figure 6 is a cross section through the chamber to a larger scale, shewing the
arrangement of the plates; and Figure 7 is a view of an electrode.
Figure 8 is a cross section of the chamber shewing a modified construction of
the bottom part thereof.
Figures 9 and 10 shew modified construction of the distributing pipes.
With reference to the drawings, it will be seen the chamber is constructed of
side walls, A, and end walls, A', and a roof A2 the breadth of the chamber being
made relatively short in relation to its length; the effect of this mode of con-
struction is that it facilitates greatly the filling of the chamber with plates and
removing the material after treatment.
In the side walls, suitable windows, a, are provided, by which the state of the
material under treatinent in the chamber can be observed from outside. At each
end and at the front other apertures, a', are provided for the double purpose of
gaining access to the chamber, and to observe the condition of the material under
treatment. The windows are glazed, (this portion being designated a²) and are
protected and covered in by movable shutters, that is to say, when the chamber
is being filled or discharged, the shutters and glazed frame are both removed from
the apertures, a', whilst merely for observation, the shutters only of the windows
are removed.
The plates, , are packed closely together in the manner shewn in Figure 6, each
plate being provided with a distance piece, , by which a certain space is allowed
between them for the passage of the converting gases. The plates, b, are supported
on transverse bearer bars, B, of wood or other suitable material, and are separated
into batches. In the example shown in the drawings the batches are separated by
the electro-negatives, or electrodes C, such negatives consisting of wooden
frames, c', the space within the frames being filled with coke, carbon or other
suitable material, the whole being wrapped in cocoamni or coir yarn matting.
By referring to Figures 1 and 6 it will be seen the frames, ', are also supported
upon the bearers B, and that they also serve as supports for the superimposed
bearers, B, of the stories above the lowermost one; thus it will be seen, the
lower bearers, B, being first placed in position, the plates, 6, with their electro-
negatives intervening, are then stowed or packed as shewn; and as the lower story
or a part thereof is completed, other bearers, B, are then placed upon the already
laid frames, C, and then again further plates, and electro-negative frames, C,
are stowed and packed upon them, and so on, until the whole chamber is filled.
This mode of packing will plainly be seen and understood upon reference to
Figures 1, 6 and 7 of the drawings.
The effection of equal, and proper distribution of the gas and vapours and the
homogeneous and equal action of such gases and vapours upon the plates, is
obtained by providing, directing and distributing boards, or partial diaphragms within
the chamber, in horizontal layers. These in the drawings are two in number, and
are designated, D', and D2; then above these a complete diaphragm D³ is
provided.
The gases and vapours are delivered into the chamber by pipes, E, running the
whole length thereof, apertures being provided in these pipes at intervals along
their length, so as to distribute such gases or vapours as equally as possible.
These pipes, it will be seen, are disposed within two chambers, E, lined with a
suitable flooring e. The gases and vapours in these chambers E, are thoroughly
distributed and will enter the stack of plates practically in equal quantities at all
points, and will therefore rise and flow throughout, and between, and over all the
plates. Then as the gases rise through the series of plates, they pass through the
central space in the first diaphragm, D having passed through which they flow
outwards through the plates in the stories above this diaphragm D, and then round
the outside edge of the diaphragm D². The effect of these diaphragms is that no
local currents are allowed to take place, and therefore, the gases are actually

page_text: caused to be thoroughly and generally distributed. The chambers, E', although
not absolutely closed, are practically closed.
The temperature of the chamber should be maintained at about from 120 to 135
degrees Fahrenheit, as at this temperature the best results are obtained.
To keep the chamber at this temperature, it will be obvious the gases or vapours
must be delivered at such a temperature as to effect such result, or of course the
chamber, as the case may be, may be artificially heated or cooled accordingly as,
and if, such gases or vapours are delivered cold or at a temperature exceeding that
such as specified.
In the arrangement shewn in Figures 8, 9 and 10, I illustrate a mode of cor-
recting the action of any irregular surrounding changes of temperature and their
effect upon the working of the chamber; also to connect any irregular action in
the distribution of the gases and vapour within the chamber.
For this purpose it
will be seen the construction of the bottom part of the chamber shown in Figures 1
to 4 is modified.
In this modification shewn in Figures 8, 9, and 10, the pipes E are set in cement
work or other suitable material, and are provided at suitable points, say about
two feet apart, with distributing pipes e¹. The upper openings of these pipes el arc
covered or capped with a perforated or gridded stoneware plate or cape, and over
this cup is provided a cover e³, capable of adjustment from the outside of the
chamber by a rod or equivalent connection e.
In Figures 8 and 9 (which show this arrangement in general end view and in
detail) the grid or perforated plate to the distributing pipes is flat, and the
cover is a flat plate, regulated from the outside by the rod et.
In the arrangement shewn in Figure 10, the distributing device consists of a
perforated cape, over which fits the regulating cover e, regulated from outside
the chamber by a cord et.
The effect and action of these devices is, that should any one part of a chamber
from some cause be over supplied, or another under supplied, a rearrangement of
the conditions can be effected by a regulation of the arrangement or adjustment of
the covers or caps e.
The plates B and the electro negative material, ², in the frame C, are coupled
by tin or other suitable strips . These strips are connected to the electrodes and
pass over and in contact with the plates. In the arrangement in the drawings, a
loose plate, horizontally disposed, is laid upon the tin strips, C³, to keep them in
position and in contact with the plates. By this means it will be seen a ready mode
of arranging the plates in electrical couples is afforded, the action of course being
that an electric current is set up between the electrodes C, and the plates, by the
action of an acid or acids and watery vapours delivered into the chamber with
the result that the process of conversion is greatly expedited.
The gases and vapours may be supplied in a vaporous state by any suitable known
means.
In lieu of using the electrodes C, a current of electricity, produced from without,
may be passed through the plates, the plates of course being stowed and put into
electrical contact with each other; in such a case, the transverse bearer bars would
have to be supported by suitable bearers equivalent to those afforded by the
frames C.
I wish it to be understood that as regards the stowing of the plates, b, I do not
confine the invention to such stowage particularly as described and set forth with
reference to the drawings, as their relative disposition as regards direction, may
be carried out in any other equivalent way to the one specified, and the same
remark obtains with respect to the supporting bars or bearers.
It will be evident that the materials of which the different parts of the chamber
and its interior fittings are made, must be such as will not corrode, or be
detrimentally affected by the gases or vapours, or inimical to the chemical and
electrical actions carried on within the chamber, such things as these are however
of course well understood.

page_text: 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 herein described mode of effecting the proper distribution of converting
gases and vapours used in the manufacture of white lead from blue lead, consisting
in guiding the gases by diaphragms or plates or equivalent distributing devices in
the chamber substantially as described.
2. In the manufacture of white lead from blue lead the form or construction of
chamber substantially as described, that is to say, a chamber of narrow width and
of relatively great length, and provided with apertures for filling and discharging,
and inspection; substantially as and for the purposes described.
3. A chamber for the manufacture of white lead from blue lead, comprising the
walls, A, and A', roof, A², doors, a', and distributing pipes, E, and diaphragmns D'
and D as set forth with reference to the drawings.
4. The herein described mode of arranging the plates in the converting chamber,
consisting in disposing them in multiple and parallel to each other, said plates
being provided with or having between them distance pieces such as ; substan-
tially as set forth.
5. In the manufacture of white lead from blue lead the combination of
electrodes, C, and plates, B, arranged together, as described, and coupled by
coupling plates or strips.
6. The herein described mode of arranging blue lead plates in the converting
chamber of white lead manufacturing process, consisting in disposing said plates in
a plurality of layers in multiple, one above the other and supporting them on
bearers substantially as described.
7. The production or manufacture of white lead from blue lead by treating blue
lead plates within a chamber to the action of gases such as specified, in conjunction
with the electric current passed through the plates and produced from without by
an electric generator; substantially as set forth.
8. In the manufacture of white lead effecting the correction of the action of
irregular surrounding changes of temperature and other causes in the chambers
in which the white lead is being produced by regulating or controlling the supply
of the gases and vapours being supplied thereto at different points; substantially
as set forth.
9. In the manufacture of white lead, the means, consisting of the distributing
pipes and regulating covers, valves, or cups, e, for regulating the supply and
distribution of gases and vapours to the chamber, as set forth with reference to
Figures 8, 9 and 10 of the drawings.
Dated this 6th day of May 1891.
CHEESBROUGH & ROYSTON,
15, Water Street, Liverpool, Applicant's Patent Agents.