IMPROVEMENTS IN the MANUFACTURE OF SULPHATE OF SODA OR POTASH AND BLEACHING POWDER
Year: 1875

page_text: LETTERS PATENT to George Dryden Mease, of the Lake Chemical
Works, South Shields, for the Invention of "IMPROVEMENTS IN the
MANUFACTURE OF SULPHATE OF SODA OR POTASH AND BLEACHING POWDER, AND
Sealed the 21st August 1875, and dated the 16th March 1875.
PROVISIONAL SPECIFICATION left by the said George Dryden Mease
at the Office of the Commissioners of Patents, with his Petition,
on the 16th March 1875.
I, GEORGE DRYDEN MEASE, of the Lake Chemical Works, South
Shields, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN THE MANUFACTURE OF SULPHATE OF SODA OR POTASH AND BLEACHING
POWDER, AND IN APPARATUS EMPLOYED THEREIN," to be as follows:-
In the manufacture of sulphates by the direct action of sulphurous
acid, air, and steam upon chlorides of sodium or potassium, it is usual
to crect the burners in one or more block or blocks, and the cylinders
for containing the salt in a separate block abutting upon or near to the

page_text: pyrites, burners, block, or blocks, the result being that the cylinders are
at very unequal distances from the burners.
I resort to the following plan of remedying this:-I erect the burners
in any convenient shape, and place the cylinders around the burners in
such manner that every cylinder at the point where the burner gas
enters it is close to the burners.
In carrying out the above object I build the burners in four double
rows in the form of a cross, and arrange the cylinders in a hollow
square around the burners, and make the points where the burner gas
enters the cylinders close to the outside ends of the arms of the cross.
It is also customary to take all the gas from the burners into one
main pipe within or around the block of cylinders, and take branches or
other short connections from this main pipe to the various cylinders. I
take separate short pipes from the burners to the cylinders.
For convenience I call the vessels for holding the salt, "cylinders,"
as that is one of the usual names, but I need not make them cylin-
drical.
I resort to the following plan for constructing the cylinders and con-
necting them to the burners and to each other:-I make cach cylinder
in two halves, with a partition wall reaching as high as the level of the
salt; I make a short connection between the burners and each cylinder
at the bottom of the upeast half of the cylinders; I make no direct
connection between the burners and the downcast half of the cylinders;
I make a short connecting pipe between the bottom of the downcast
half of cach cylinder and the bottom of the upcast half of the cylinder
next in order to it; I make the cylinders of metal or wrought iron at
the bottom; I line them inside with brick; I make the inside lining
walls of the sides to incline inwards towards each other, and I enclose
them at the top with a circular arch, so that the sides can the better
resist the outward thrust of the sulphate; this shape also facilitates the
discharge; outside this lining I build a casing of loose half-thick firc-
bricks on edge; I light a fire inside at this stage, and keeping it lighted
day and night until the exterior work is finished, so that the inside
brickwork may be the size and shape that it is when at regular work;
I apply a layer of sand outside the course of loose fire-bricks, and I
damp the sand with water or with a solution of salt, and mould a thin
layer over the half-thick bricks; as soon as one layer of sand dries I

page_text: nouid on another, and so on until I have as muen sand as I wisII.
11 1
damp the sand with a solution of salt I use the solution only strong
enough to set the sand without interfering with its non-conducting
power by closing up the air spaces.
In building up the next coating I change the shape of the section to
that of a square by moulding on horizontal layers on the sides and
radial layers over the top of strong and yet very porous concrete,
moulded to form by a wooden frame. I form this coating of ground
scars or clinkers set with as little as possible of the best Portland
cement; I prefer not mixing any sand with the cement, as that would
interfere with the non-conducting power of the concrete by making it
too close.
I put a horizontal layer of concrete on the top to distribute the strain
and vibration; when the last coating is set I let the fire go out; I cover
the top by sheet iron and the sides by lead to render the whole gas-tight.
On the top of cylinders I place a railway; on this railway I run the
salt wagons for filling the cylinders.
I make holes in the bottom of the cylinders to discharge the sulphate
into wagons, and to support the materials and allow free passage to the
gases I employ grates or skids in radial or other segments fastened by
hooks or by other means at the circumference, and with a moveable
support to cach segment at the centre, so that as each support is
knocked away a segment of the grate falls sloping to the discharging
hole.
I work the burners in the following manner so as to get a hot gas
containing as little free oxygen or as much vapour of sulphur as I
wish.
I heat the air required for the combustion of the pyrites by hot metal
pipes or other suitable means and pass it into the burners alternately
with the hot air, and when I require a gas containing free sulphur
vapour I superheat the steam, otherwise I employ steam at its natural
temperature together with hot air. I place the furnace for heating the
air and steam in the space formed by the intersection of the rows of
burners.
If the above plan does not give me as much heat as I wish in the
working cylinder (by the " working cylinder "I mean the one into

page_text: which for the time being the burner gas passes direct) I adopt the
following plan:-I curtail the air to the burners until scarcely any free
oxygen passes into the cylinder, or if necessary I vaporize sulphur into
the cylinder and burn it within the cylinder by means of air heated in
the following manner :-I construct a furnace of metal pipes, or I prefer
one on the regenerative principle, and pass the air required through
either furnace to the cylinder as hot as I can make it. I prefer to use a
coke fire rather than carbonic oxide or coal to the furnace, and I drive
the fire with a hot or cold blast. I supply the blast for the combustion
and the air for the cylinder by a power fan attached to the furnace. I
place whichever plan of furnace I use on wheels on a railway just
outside of the working cylinder, so that the hot air passes direct into the
cylinder.
The heat absorbing bricks which I employ in the furnace I make
feather edged instead of square. I place each alternate brick edge up
and edge down, and I place the row above, so that feather edge points
to feather edge, and broad edge to broad edge. The same arrangement
is applicable to other regenerative furnaces. I pass the exhaust steam
from this fan engine into the general steam pipe or through the furnace
into the cylinder. I pass hot air or steam from a furnace of this con-
struction into any of the other cylinders if they require it, but it is not
necessary if the working cylinder is as hot as the sulphate can bear. I
put the regenerative furnace and the fan and engine on separate
carriages, so that when the furnace is off for repairs the fan and engine
can work on to another one.
In first heating up the cylinders I do so by a coke fire attached to the
bottom hole. When at regular work I heat up the cylinders newly
charged with chlorides, and at the same time cool the finished sulphates
as follows: I attach a power fan to the cold chloride cylinder and open
the connection between it and the hot sulphate cylinder, and open the
further bottom hole in the sulphate cylinder and draw the heat out of
the sulphate cylinder into the chloride cylinder. I put this fan and
engine on wheels on the railway just outside of the cylinders. I pass
the exhaust steam from this engine into the general steam pipe for
supplying the salt cylinders. Or I may employ the draught of a
chimney instead of a draught obtained by a power fan. I draw the
gases through the cylinders by a power fan and use the exhaust steam
from the engine to supply the cylinders. I drive the pressure fan to

page_text: supply hot air to the burners by the same engine, either directly or
indirectly, that drives the exhaust fan, so that the two fans may bear a
constant relation to each other.
When desirable I pass all or any of the exhaust steam passing from
the various fan engines either into the burners or through the regene-
rative furnaces. The usual plan of preparing the chlorides of sodium or
potassium is to have a dry loose layer upon the drying flats, and to put
upon this a layer which has been previously damped.
I put down the top layer in its natural state, and level it, and then
add the requisite water on the top. I do this in the following manner:-
Above the level of the drying flat I place a tumbling box filled by
water, the flow of which is regulated by a tap. The tumbling box
delivers into any suitable vessel (such as a funnel), which is connected
to a flexible hose. The hose terminates in a rose made large enough for
the jets of water to cover the space intended to be wetted by one fall of
the tumbling box. The bottom of the rose is divided into sections by
knife-like edges, so that by putting it upon the salt it is wetted and
divided into separate blocks in one operation.
The flow of water is regulated so that the tumbling box takes a
second or two longer to fill than the rose takes to empty, so that after
one flow of water ceases there is time to remove it to a new place before
the next descent of water. This plan completely changes the crystalline
structure of the salt into a very porous, fibrous, or striated structure.
The salt should not be pressed or walked upon after being wetted, as that
makes it too dense.
In the centre of the space formed by the intersection of the rows of
burners I place on columns above the air heating furnace a cylinder
constructed in the same manner as the sulphate cylinders, and I conduct
into this all the exit pipes for conveying the hydrochloric acid from the
cylinders, and use it either as pure sulphate cylinder or for the produc-
tion of chlorine. I place above and between each cylinder thin
upright metal pipes, so that I can cool the gases by letting them have
access to these pipes if the chemical action at any stage of the process
becomes too energetic.
In forming chlorine from hydrochloric acid by catalysis or decompo-
sition by heat I employ the following plan:-I construct a furnace on

page_text: the regenerative principle heated by coke or carbonic oxide. I regulate
the pressure of the fuel gases and the acid gases by fans, blowers, or
other apparatus driven by steam. I heat the acid gases sufficiently to
decompose them, and then cool them suddenly down, so that they have
not time to reunite in cooling. I do this either by injection of water
into the hot gases, or by exposing them to large thin surfaces of good
conducting material covered by a water jacket, or both means combined,
or any other of the usual means of rapid cooling.
I adopt the same plan of cooling the gases suddenly when other
processes are used, in which the chlorine is formed by the decompo-
sition of hydrochloric acid or a salt at a temperature exceeding 250°
Fahrenheit.
In forming chlorine by the gaseous process I employ the same descrip-
tion and construction of cylinders as I use for manufacturing sulphates,
and I put a set of pipes of any of the usual forms between each cylinder
for heating or cooling the gases. I so arrange these pipes that by letting
the products of combustion from a fire pass over them I can heat them,
or by letting cold air flow over them I can cool them.
I charge the cylinders with the following ingredients:-I mix raw or
oxidized copper precipitate with common salt, and form it into a porous
mass in the same way as I have already described. I prefer in this case
a salt with fibrous walls and cellular cavities, and I form it as follows:-
I dry common salt and grind it finely, and then mix one part of this
with from four to six parts of common salt, and with as much raw or
oxidized copper precipitate as I think nccessary. I wet and prepare this
mixture in the same way as already described.
I adopt the following plan of slaking the lime at a low temperature
for the manufacture of bleaching powder :-I put the lime upon plates
or flues heated by hot water pipes, steam pipes, or fuel. I prefer metal
plates with hot water pipes below, and I add to the lime such a propor-
tion of hot water or boiling water as would make the lime damp at the
bottom if it was slaked on a cold surface. If the lime is hydraulic or
under burnt the proportion of water I use will make it damp at the
bottom, and in such a case I leave it on the plates or flues until it is as
dry as I wish. I do not add such a proportion of water as will make
cream of lime, but such a proportion that if the lime be good it will not
be damp anywhere, but be thoroughly slaked, and in addition contain

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Dryden Mease in the Great Seal Patent
Office on the 16th September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DRYDEN MEASE, of the Lake Chemical Works, South Shields, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of March, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George Dryden Mease, Her special
license that I, the said George Dryden Mease, my executors, adminis-
trators, and assigns, or such others as I, the said George Dryden Mease,
my executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF SULPHATE OF SODA OR POTASH AND BLEACHING POWDER,
AND IN APPARATUS EMPLOYED THEREIN," upon the condition (amongst others)
that I, the said George Dryden Mease, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands

page_text: Mease's Improvements in the Manufacture of Sulphate of Soda, &c.
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said George Dryden Mcase, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement thereof, that is to say :-
This Invention has for its object improvements in the manufacture of
sulphate of soda or potash and bleaching powder, and in apparatus
employed therein.
In the manufacture of sulphates by the direct action of sulphurous
acid, air, and steam upon chlorides of sodium or potassium, it is usual to
erect the burners in one or more block or blocks, and the cylinders for 1
containing the salt in a separate block abutting upon or near to the
pyrites, burners, block or blocks, the result being that the cylinders are
at very unequal distances from the burners.
I adopt the following plan of remedying this:-I erect the burners
in any convenient shape and place the cylinders around the burners in
such a manner that every cylinder at the point where the burner gas
enters it is close to the burners.
I prefer to build the burners in four double rows in the form of a
cross, and arrange the cylinders in a hollow square around the burners,
and make the points where the burner gas enters the cylinders close to 2
the outside ends of the arms of the cross.
It is also customary to take all the gas from the burners into one
main pipe within or around the block of cylinders, and take branches or
other short connections from this main pipe to the various cylinders. I
use separate short pipes or connections from the burners to the a
cylinders.
For convenience I call the vessels for holding the salt "cylinders," as
that is one of the usual names, but I do not make them cylindrical.
Figure 1 shows a ground plan of burners and cylinders. The shaded
cross shows the burners. The burners are of ordinary construction, and a

page_text: say four in each block, sixteen in all; they are connected by passages
with valves by which the gas can be passed from one to another.
A shows the pipes to convey the gas from burners to cylinders; only
one of these pipes is in use at a time, the others being closed; B shows
the cylinders; C, connecting pipes between the cylinders, by these pipes
all the cylinders which are at work are connected together into a series;
D', exit pipes from cylinders to a circular pipe in the centre from which
a pipe passes away to convey the hydrochloric acid gas to "Deacon
cylinders" for making chlorine, or to a condenser in which the acid gas
is dissolved in water. These pipes are carried upon girders or tension
rods and struts. An out draft is maintained by means of a steam jet.
D" shows another method of exit pipes in which the gas passes out from
the cylinders through a short horizontal pipe into an upright one, and
thence by a short pipe into the main exit pipe d. E shows the pipes for
drawing air from the hot sulphate in one cylinder upon the cold salt in
another, both cylinders being at this time disconnected from tho
working series. The draught is obtained by means of a steam jet.
F shows the position of the doors at the corners of the block.
I use the following plan for constructing the cylinders and connecting
them to the burners and to each other. The cylinders are vaulted
structures of oven-like form. I make the sides of brick and form the
top of a circular or elliptical arch; I make cach cylinder in two halves
with a partition wall reaching nearly to the top or as high as the level
of the salt. The gas is made to ascend through the salt on one side and
to descend on the other. I make the short connection between the
burners, and each cylinder at the bottom of the upcast half of the
cylinders; I make no direct connection between the burners and the
downcast half of the cylinders; I make a short connecting pipe between
the bottom of the downcast half of cach cylinder and the bottom of the
upcast half of the cylinder next in order to it. I make a hole in the
centre of the bottom of each division of the cylinder to discharge the
sulphate into wagons and slope the bottom from the doors towards the
hole; I place grates over the bottoms and I remove portions of these grates
so as to discharge the sulphate through the central hole in the bottom.
I use the following plan of heating up the cylinders newly charged
with chlorides, and at the same time cooling the finished sulphates; I
draw a stream of air through the hot sulphate of soda into the cold salt
by any suitable air exhauster.

page_text: Figure 2 is a plan; Figure 3, a longitudinal section, and Figure 4, a
cross section of a "cylinder" constructed according to my Invention; A
are the central discharging holes; B, C, portions of the grates that can
be taken out or moved out of the way. The rest of the grates rest upon
pillars of brick or metal.
In Figure 3 arrows show the course of the gas from one cylinder to
another through D', D". D' and D" in Figure 2 show the method of
connecting and disconnecting the pipes. All the pipes shown in Figure 1
are connected and arranged in the manner here shown. In D¹ the
passage is shown open, the gas passes through two pipes with a space of
a few inches between the ends, which space is covered by a ring or
ferrule of two flanged semicircles fastened by clips and wedges, and sand
is filled in around the joint. In D" the passage is closed, the ferrule is
put aside and a circular cap or damper is placed on the end of each pipe.
Shutters are put up as shown at d to support sand around the pipes.
All the pipes throughout the structure arc protected in a similar
manner to reduce the loss of heat as far as possible; E shows columns
to support the roof and railway, the columns also act as binders; F
shows tension rods passing round the cylinder; G shows the metal
casing, and G¹ girders, which are rivetted to the side casing if of iron or
strutted in off the tension rods if the side casing is of lead; H shows the
partition wall; I, metal plates around the discharging holes. A hopper
and a sliding shutter is temporarily fastened to the flange around this
hole when the sulphate is discharged to regulate the delivery; K are
filling holes fitted with metal covers; through these holes the cylinders
are filled with salt to within about six inches of the top; L sand, ground
scars, or such like material covering the arched roof of the cylinder and
filling the cells or hollows left in building the side walls.
In putting the apparatus to work the cylinders are filled with salt,
and seven of the cylinders are connected into a scries which series is
made to communicate at one end by one of the pipes A, Figure 1, with
the burners, and at the other end with one of the pipes D¹ or D¹ in
which as before-mentioned an out draft is maintained by means of a
steam jet. Coke fires are then lighted in the burners and the products
of combustion are led through the series of cylinders until they are
heated up. The burning of pyrites is then commenced and it is carried
on continuously until the conversion of the salt in the first cylinder of
the series is completed. This cylinder is then cut off from the series,

page_text: the burner gas being conducted first into the cylinder, which up to this
time has been the second of the series. The sulphate in the first
cylinder is now cooled by drawing a current of air through it. The
cylinder is coupled with the cylinder which up to this point has been
out of work, and a steam jet is applied to suck air into and through the
hot cylinder, and thence into, through, and out of the cold cylinder; this
operation is continued until the heat has been transferred with as little
loss as possible from the hot sulphate to the cold salt. The cylinder
containing the salt is then coupled up so as to constitute the last
cylinder of the working series, and the sulphate cylinder is discharged.
The manufacture of sulphate of potash is similar to that of sulphate
of soda.
I would remark that the construction of the cylinders, each with a
central partition arranged in such manner that the gas ascends on onc
side of the partition and descends on the other side, is an important
feature of my Invention, and is applicable to cylinders differing in other
respects from those shown in the Drawings. The usual plan of pre-
paring the chlorides of sodium or potassium for this process is to have a
dry loose layer of salt upon the drying flats, and to put upon this a layer
of salt which has been previously damped throughout its mass.
I put the top layer down in its natural state, and add the requisite
water on the top. I prefer to do this as follows:-Above the level of the
drying flat I place a tumbling box filled by water, the flow of which is
regulated by a tap. The tumbling box delivers a measured quantity of
water at regular intervals into any suitable vessel (such as a funnel),
which is connected to a flexible hose. The hose terminates in a rose which
under the control of the workman delivers the water upon the salt. The
space to be wetted by cach fall of the tumbling box is marked out by a
series of blades or cutting irons which divide the salt into blocks. The
cutters are arranged in the form of a square, and the frame covers an
area of about a square yard, the square being subdivided into nine parts,
each a square foot.
The flow of water is so regulated that the tumbling box takes a
second or two longer to fill than the rose takes to empty, and that after
one flow of water ceases there is time to remove the cutter and rose to a
new place before the next descent of water. The salt being thus
uniformly wetted all over, the surface is left on the drying flats to dry

page_text: and harden. This treatment completely changes the crystalline
character of the salt into a very porous, fibrous, or striated structure.
The salt should not be pressed or walked upon after being wetted, as
that makes it too dense. The salt is cut up off the drying flat in the
blocks a foot square.
In order to avoid the formation of dust in breaking the salt I pass
blocks of salt through one pair of cutting rolls such as are now used for
breaking the salt, and split it along the fibre into strips about four
inches long (the thickness of the cake), by an inch and a half thick: At
the present time it is usual to employ two pairs of cutting or breaking
rolls.
I use the following plan for slaking lime at low temperatures for the
manufacture of bleaching powder from chlorine gas. I put the lime
upon plates or flues heated by hot water pipes, steam pipes, or fuel.
I prefer metal plates with hot water or steam pipes below, and I add to
the lime such a proportion of water as might make the lime damp at the
bottom if it was slaked upon a cold surface, my object being not only to
thoroughly slake the lime, but also to communicate to it as much free
moisture as it will hold when in a light pulverulent state.
If a batch of lime is more or less hydraulic or under burnt the
proportion of water I use will make it damp at the bottom, and in such
a case I leave it on the plates until it is as dry as I wish. I do not add
such a proportion of water as will make cream of lime, but such a pro-
portion that if the lime be good it will not be damp anywhere, but be
thoroughly slaked and in addition contain moisture equally disseminated
throughout the mass. This moisture may amount to as much as half an
equivalent. When I use boiling water I prefer about equal weights of
lime and water.
I use the same plan for measuring the water for the lime, and
applying it as described above for wetting the salt.
I sometimes use lime slaked as above, mixed with lime slaked in the
ordinary way.
Having thus described the nature of my said Invention and the
manner of performing the same I would have it understood that I
claim,-
First. The arrangement of the cylinders in a series surrounding the
burners, so as to obtain a more direct delivery of the gas from the

page_text: burners into the cylinders, substantially as described in respect to
Figure 1.
Second. The construction of the oven-like vaulted "cylinders," sub-
stantially as described,
Third. The construction of the cylinders each with a central partition
and arranged in such manner that the gas ascends on one side of tho
partition and descends on the other side, substantially as described.
Fourth. The means for cooling the sulphate in the cylinder and
transferring its heat to a fresh charge of salt, substantially as described.
Fifth. The means for preparing the salt, substantially as described.
Sixth. The means for preparing lime for the manufacture of bleaching
powder from chlorine gas, substantially as described.
Seventh. The improvements in the manufacture of soda or potash and
bleaching powder and in apparatus employed therein, substantially as
described.
In witness whereof, I, the said George Dryden Mease, have here-
unto set my hand and seal, this Tenth day of September, in
the year of our Lord One thousand eight hundred and seventy-
fivc.