AN IMPROVED PROCESS AND APPARATUS FOR OBTAINING AMMONIA
Year: 1882

page_text: LETTERS PATENT to Friedrich Lorenz Director of the "Chemische Duënger-
fabrik Rendsburg" of Rendsburg in the Kingdom of Prussia and Empire of
Germany for an Invention of "AN IMPROVED PROCESS AND APPARATUS FOR
OBTAINING AMMONIA "
PROVISIONAL SPECIFICATION left by the said Friedrich Lorenz at the
Office of the Commissioners of Patents on the 16th December 1882.
FRIEDRICH LORENZ director of the "Chemische Duëngerfabrik Rendsburg" of
Rendsburg in the Kingdom of Prussia and Empire of Germany
"AN IMPROVED
PROCESS AND APPARATUS FOR OBTAINING AMMONIA
"
The object of the invention is by the employment of certain improved apparatus
to obtain the ammonia contained in the hot gases of bone or other furnaces.
To carry out this object the hot gases are mixed with aqueous gases or steam
during their passage from the furnace to the condenser. As the first step of the
process consists in the reduction of the temperature of the hot gases to facilitate
the second step: the condensation: the heat of the gases is made use of for
producing the aqueous gases. In the channel for the hot gases is arranged a metal
plate, which is heated by these passing gases, so that water, flowing upon the plate,
is evaporated and the produced aqueous gases are mixed with the other gases.
Before entering the condenser the so treated gases are carried through the
regenerator for the double purpose of reducing still more their temperature and of
heating at the same time cold gases, which, coming from the water tower, pass the
regenerator in their way to the acid tower.
The construction of the regenerator may be varied according to circumstances
but in all cases it must be such, that the pipe or vessel, carrying the hot gases,
surrounds or jackets the pipe or vessel which carries the cold gases, or vice versa.
From the regenerator the still hot gases, though of a lower temperature than
before entering the regenerator, pass into the condenser which may be
advantageously constructed as a surface condenser.
The condensed ammonia fluid is drawn off from a connecting vessel whilst the
remaining gases are carried to the lower part of the water tower, from where
D

page_text: they pass to its top and leave it there cold and deprived of the greatest part of the
ammonia.
The fluid containing the ammonia is drawn off from the bottom of the tower.
To gain also the remaining part of the ammonia these cold gases are reheated
and treated in the acid tower in the same way as before in the water tower, since
the hot state of the gases facilitates the oscillatory motions of the molecules of the
formed product, and therefore also the power of the diluted acid of absorbing
ammonia.
For this purpose the cold gases are passed as above mentioned, through the
regenerator and enter in a heated- state, the lower part of the acid tower, which
they leave, deprived of all ammonia, at its top and thence pass away by the
chimney. The acidulated ammonia fluid is drawn from the bottom of the acid
tower, mixed with the fluid or lye of the water tower and either evaporated for
giving sulphate of ammonia, or used in lieu of water in the water tower.
The two mentioned towers are vessels, the water tower of iron, the acid tower of
lead, filled with pieces or lumps of, firebrick or similar substances, which latter are
wetted by water or lye, respectively by diluted sulphuric acid, which is sprinkled
on them from reservoirs at the top of the towers.
By these means the surface of the descending fluid is increased thereby
increasing also its power of absorbing the ammonia of the gases ascending the
towers.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Friedrich Lorenz in the Great Seal Patent Office on the 13th June
1883.
FRIEDRICH LORENZ, director of the "Chemische Duëngerfabrik Rendsburg" of
Rendsburg in the Kingdom of Prussia and Empire of Germany "AN IMPROVED
PROCESS AND APPARATUS FOR OBTAINING AMMONIA
"
The object of the invention is by the employment of certain improved apparatus
to obtain the ammonia contained in the hot gases of bone or other furnaces.
To carry out this object the hot gases are mixed with aqueous gases or steam
during their passage from the furnace to the condenser. As the first step of the
process consists in the reduction of the temperature of the hot gases to facilitate
the second step (the condensation) the heat of the gases is made use of for
producing the aqueous gases. In the channel for the hot gases is arranged a metal
plate which is heated by these passing gases, so that water flowing upon the plate
is evaporated and the produced aqueous gases are mixed with the other gases.
Before entering the condenser the so treated gases are carried through the
regenerator for the double purpose of reducing still more their temperature and of
heating at the same time cold gases which coming from the water-tower pass
through the regenerator on their way to the acid-tower.
The construction of the regenerator may be varied according to circumstances
but in all cases it must be such that the pipe or vessel carrying the hot gases
surrounds or jackets the pipe or vessel which carries the cold gases or vice versa.
From the regenerator the still hot gases though of a lower temperature than before
entering the regenerator pass into the condenser which may be advantageously
constructed as a surface condenser. The condensed ammonia-fluid is drawn off
from a collecting vessel whilst the remining gases are carried to the lower part
of the water tower from whence they pass to its top and leave it there cold and
deprived of the greatest part of the ammonia. The fluid.containing the ammonia
is drawn off from the bottom of the tower. To gain also the remaining part of
the ammonia these cold gases are reheated and treated in the acid-tower in the
same way as before in the water-tower, since the hot state of the gases facilitates
the oscillatory motions of the molecules of the formed product and therefore also
the power of the diluted acid of absorbing ammonia. For this purpose the cold
gases are passed as above mentioned through the regenerator and enter in a heated
state the lower part of the acid-tower which they leave, deprived of all ammonia,
at its top and thence pass away by the chimney. The acidulated ammonia fluid is
drawn from the bottom of the acid-tower mixed with the fluid or lye of the water-
tower and either evaporated for giving sulphate of ammonia or used in lieu of
water in the water-tower. The two mentioned towers are vessels, the water-tower
of iron, the acid-tower of lead, filled with pieces or lumps of fire brick or similar
substances, which latter are wetted respectively by water or lye and by diluted
sulphuric acid which is sprinkled on them from reservoirs at the top of the towers.
By these means the surface of the descending fluid is increased thereby increasing
also its power of absorbing the ammonia of the gases ascending the towers.
And in order that the said Invention may be more clearly understood and
readily carried into effect I will proceed aided by the accompanying drawings
more fully to describe the same.

page_text: The hot gases of bone or other furnaces containing ammonia are carried through
the channel a to the condenser f passing through the regenerator b. "In the
channel a is provided a large iron plate c which is heated by the passing hot gases
so that water flowing through the pipe d upon this plate c is evaporated and mixed
in the form of steam with the gases. This steaming of the gases greatly facilitates
the separation of the ammonia from the non condensable part of them as well in
the cooler or condenserf as in the towers. The gases go from the top of the tube
or regenerator b through pipe e into the large shallow cooler or condenser f the
upper part of it is filled with cold flowing water and decreases the temperature of the
gases. g. g. are water pipes. From the basin of the condenser f the pipe & carries the
water to the above mentioned plate c. The gases pass through a pipe in the bottom
of the cooler finto the smaller vessel h and from there through the pipe j into the
lower part of the tower i. The tower'i made of sheet iron is filled with pieces or
lumps of fire brick or other suitable material upon which drips the fluid of the
reservoir at the beginning of the operation consisting of water presenting a very
large absorbing surface to the gases in their passage from the bottom to the top of
the tower i. The lye having arrived at the bottom of the tower i flows through
the pipe j into the vessel h and is drawn off by the trapped pipe
The remaining gases still containing ammonia are carried through the pipe n to
the acid tower p filled also with pieces or lumps of fire brick or other suitable
material which are wetted with diluted sulphuric acid dripping down from the
reservoir o on top of the tower p.
Notwithstanding that the diluted acid has a great affinity for the ammonia, its
absorbing power is increased when the gases in a hot state are brought in contact
with the acid, as the oscillatory motions of the molecules of the formed product are
increased by heat, facilitating the absorption of the ammonia. To protit by this
experience, the pipe n leading from the tower i to the tower p is carried through
the tube or regenerator b carrying the hot gases from the channel a to the
condenser f. The hot gases give off a portion of their heat to the cold gases
passing through the pipe n so that the latter enter the lower part of the acid-
tower p in a hot state. The absorption may be supported by the additional
employment of steam injected into the tower.
The gases in the tower p leave it cooled and deprived of all ammonia through
The
the pipe q on top of the tower and are carried off by the chimney r.
ammonia-containing acidulated fluid passes into a reservoir not shown in the
drawing and it is from there after having been saturated with the lye running from
the tower either evaporated for giving sulphate of ammonia or it is pumped
again into the reservoir to be employed in lieu of water.
To increase the heating action of the hot gases in the tube or regenerator 6 the
pipe n may consist as far as it is jacketed by the tube 6 (instead of a single pipe)
of a bundle of smaller pipes n¹ (Figure 3) presenting a larger heat absorbing
surface, or the cold gases may as shown in Figure 4 surround a bundle of pipes n¹
through which the hot gases pass.
I would here remark that the construction of the cooler or condenser ƒ may be
varied according to local circumstances to the temperature of the entering gases
and other causes important to the manufacture as well as the size and position of
the various parts of the apparatus without departing from the nature of the
invention.
I am aware that the obtaining of ammonia from the gases of furnaces is well
known but what I consider new and desire to secure by letters patent is :-
First The process of obtaining ammonia from the hot gases of bone and other
furnaces by first mixing them with water vapors or steam, secondly-cooling the mix-
ture and collecting the ammonia-containing fluid; thirdly-carrying the remaining
gases through a tower filled with lumps of fire brick or other suitable material in a
direction opposed to the water or diluted lye of sulphate of ammonia, which dripping
from a reservoir on top of the tower wets its contents and absorbs the ammonia;
fourthly the treatment if necessary of the remaining gases after heating them

page_text: during their passage to a second tower similar to the water-tower, with diluted
acid in this second tower into which steam may be admitted; fifthly mixing the
fluid product with the ammonia-containing fluid from the first tower, and sixthly
re-using in the tower or towers the fluid product until it has absorbed enough
ammonia substantially as herein described.
Secondly. An apparatus for the purpose of obtaining ammonia from the gases
of bone and other furnaces by the described process-consisting of the iron plate c
in the channel a, the tube or regenerator b, the cooler or condenser f, the vessel h,
the water-tower with its reservoir if necessary the second or acid-tower p with
its reservoir o and the connecting pipes e. j. n. q of which b serves as a heater for
the jacketed part of the pipe n operating and arranged substantially as herein
shown and described.
Thirdly. The metallic plate c in the channel a heated by the gases from bone
or other furnaces in combination with water dripping on it through the pipe d for
the purpose of mixing the gases with the produced aqueous vapour or steam sub-
stantially as herein shown and described.
Fourthly The tube b in combination with the pipe n or the pipes n¹ as far as
they are jacketed by the tube b as shown in Figures 3 and 4 for the purpose of
heating alone or in combination with steam the gases passing from the water-
tower i to the acid-tower p substantially as herein shown and described.
In Witness whereof I the said Friedrich Lorenz have hereunto set my hand
and seal this fourth day of June in the year of Our Lord one thousand
eight hundred and eighty three.
FRIEDRICH LORENZ (L.S.)