IMPROVEMENTS IN THE MANUFACTURE OF SALT
Year: 1864

page_text: LETTERS PATENT to Dennis Hall, of Winsford, in the County of Chester,
Engineer, and August Ludwig Roosen, of Manchester, in the County
of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF SALT."
Sealed the 10th January 1865, and dated the 23rd July 1864.
PROVISIONAL SPECIFICATION left by the said Dennis Hall and August
Ludwig Roosen at the Office of the Commissioners of Patents, with
their Petition, on the 23rd July 1864.
We, DENNIS HALL, of Winsford, in the, County of Chester, Engineer, and
AUGUST LUDWIG ROOSEN, of Manchester, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF SALT," to be as follows:-
The object of our Invention is, first, to reduce the cost of making salt from
brine by a more perfect utilization of the fuel for evaporating the brine; and,
secondly, to reduce the first cost of salt pans.
To attain this object we propose to construct a salt pan or a range of salt
pans of a circular or any other suitable shape of brick or any other suitable
material, and to cover such salt pan or pans all over with a brick arch or
otherwise to prevent all radiation of heat from the brine under such arch or
At one end of the salt pan or pans we construct a furnace, consuming
as perfectly as can be obtained its smoke, and we allow the heat from such
furnace to pass over the surface of the brine, instead of passing under the salt

page_text: pan or pans as has hitherto been customary. The steam evolving from the
evaporating brine, together with the products of combustion, may then serve to
heat one or more open salt pans in the usual manner. In combination with
the above we propose to use the machinery now known and in use for
extracting the salt from the salt pan or pans for agitating the brine. It is
preferred to construct the covered salt pans in brick or any other suitable
material cheaper than iron, also to give them a circular shape, and to supply
them with pockets into which the salt is raked by revolving rakers, and from
which the salt may be removed by hand or by any suitable mechanical
contrivance.
The shape, construction, and materials of the pans and rakers may be
varied, the main feature of our Invention being the combination of surface
evaporation with machinery for extracting the salt from the pan or vessel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Dennis Hall and August Ludwig Roosen in the Great Seal
Patent Office on the 18th January 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, DENNIS
HALL, of Winsford, in the County of Chester, Engineer, and ANGUST
LUDWIG ROOSEN, of Manchester, in the County of Lancaster, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of July, in the year of our Lord One
thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her beirs and successors, give and grant unto us, the
said Dennis Hall and August Ludwig Roosen, Her special license that we,
the said Dennis Hall and August Ludwig Roosen, our executors, administra-
tors, and assigns, or such others as we, the said Dennis Hall and August
Ludwig Roosen, our 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 MANU-
FACTURE OF SALT," upon the condition (amongst others) that we, the said
Dennis Hall and August Ludwig Roosen, our, executors or administrators, by
an instrument in writing under our or their, or one of our or their hands and
seals, should particularly describe and ascertain the nature of the said

page_text: 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 we, the said Dennis Hall and August Ludwig
Roosen, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement (that is to say) :-
The object of our Invention is to reduce the cost of making salt from brine
by economising the fuel employed for evaporating the brine and reducing the
wear and tear of the salt pans.
To obtain these objects we construct a salt pan or a range of salt pans of a
circular or any other suitable shape, of brick or other suitable material, and we
cover such salt pan or pans either partially or entirely with a brick arch or
otherwise to prevent the radiation of heat from the brine. At one end of the
salt pan or pans a furnace is erected, consuming as perfectly as can be
obtained its smoke, and we allow the heat from such furnace to pass over
the surface of the brine, instead of passing under the salt pan or pans as has
hitherto been customary. The steam evolving from the evaporating brine,
together with the products of combustion, may then serve to heat one or
more open salt pans in the usual manner.
And in order that our Invention may be more fully understood, we annex
hereto a Sheet of Drawings showing a convenient mode of carrying our
Invention into operation.
Fig. 1 is a longitudinal section through the middle of the salt pan and
through the middle of one of the two furnace grates; Fig. 2 is a plan, the
line A, B, in this plan shows where the longitudinal section is taken; Fig. 3
is a cross section through the line C, D, of the covered pan and cover; Fig. 4
is a cross section through the line E, F, of the partition wall between the
cover and the furnace, showing the two openings through which the heat is
admitted under the arch or cover and to the surface of the. brine, and also the
entrance to the relief flue under the pau; Fig. 5 is a cross section through
the lino G, H, of the vertical flues which connect the furnaco with the relief
flue under the pan; and Fig. 6 is a cross section of the furnace through the
line I, K.
The furnace is of the usual and most simple construction, consisting of two
horizontal grates a, a, seperated by a partition wall of the same height as
the dash wall or bridge c, and one arch spanning the width of both grates.
Thus the flames and products of combustion from both grates may mix with
each other before they pass over the dash wall, and as the two fires are fed

page_text: alternately, the one burning bright while the other is fed, the bright fire will
to a great extent consume the smoke of the fresh fire. To prevent large
volumes of smoke, which cannot well be avoided when the fire is first lighted
or while the grates are being cleaned, we have provided a pair of dampers d,
the position of which is shown in Fig. 1. These dampers are made to swivel
on a horizontal shaft, and when they are lying down they shut the products of
combustion from the vertical flue e and relief flue f, and leave the passage
open to the brine in the pan 9. When the fires are first lighted or when the
grate bars are being cleaned the dampers d are turned up; they then close the
passages leading to the cover over the brine pan, and open the vertical flues 6,
thus allowing the smoke to pass under the pan g without touching the brine.
In the present case the brine pan is divided into two parts of unequal
lengths, of which the shorter one being nearest the furnace is covered over.
The division plate, which separates the two parts does not reach from one
side of the pan to the other, but leaves a passage at each side for the brine to
circulate from the covered pan into the open back pan. This division plate
also forms one side of a box of iron plates h of the same height as the rim of
the pan, and surrounding a hole cut into the bottom of the back pan. Round
this iron box a brick flue is built which opens into the cover, and which
carries the steam and heat from under the cover to the under side of the back
pan. The cover is fitted between this flue and the end wall of the furnace,
see Figs. 1 and 2, and it is constructed quite independently of the other parts
of the apparatus. The top of the cover consists of a series of hollow blocks
of fire-clay marked K, which are joined together by an iron framing 1, by
which they are also suspended from a wooden framing i constructed over the
pan. The sides of the cover are made of iron plates, which are hooked on to
the iron framing 1, and they are lined inside with fire-bricks. These sides or
curtains dip about one inch into the brine, and the under side of the cover is
about two feet distant from the surface of brine. The cover is of considerably
less width than the pan, and the uncovered parts of the pan at each side serve
as pockets to enable the men to draw the salt from under the cover. The
cover is made in three parts, each having an independent iron framing. The
hollow blocks of the cover are placed so that the holes communicate with one
another longitudinally, and the two end blocks of each row of blocks being
shut up an isolated column of air is obtained, which greatly tends to prevent
radiation of heat. The blocks are suspended and connected to the iron
framing by cross bars, which have their ends bent down and rest on the
outer framing, thus holding the two side frames securely together.
The foregoing description is only given as one mode of applying our

page_text: Invention, but our Invention may be applied in many other ways;
it may
also be worked in combination with the known machinery for raking the salt
pan under the cover into the pockets. Also in combination with circulating
pans or otherwise, and we wish it most particularly to be understood that we
do not claim any particular arrangement or combination of apparatus, but
what we claim as of our Invention of improvements in the manufacture of
salt is the application of surface heating for the evaporation of brine.
In witness whereof, I, the said Angust Ludwig Roosen, have hereto
set my hand and seal, this Sixteenth day of January, One thousand
eight hundred and sixty-five.
AUGUST LUDWIG ROOSEN. (L.S.)