JMPROVEMENTS IN THE METHOD OF, AND APPARATUS FOR, RECOVERING AMMONIA FROM GASES OF VARIOUS KINDS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of the
Commissioners of Patents on the 10th January 1883. A communication
from Ferdinand Philipp, a person resident at Romanshorn in the Republic of
Switzerland
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany, " JMPROVEMENTS IN THE
METHOD OF, AND APPARATUS FOR, RECOVERING AMMONIA FROM GASES OF VARIOUS
KINDS "[A communication from Ferdinand Philipp, a person resident at
Romanshorn in the Republic of Switzerland]
This invention relates to the recovery of ammonia from various gases by means
of a suitable heated solution of acid, and preferably sulphuric acid, which is
presented to the said gases in the form of spray, and to apparatus therefor.
The said apparatus comprises two leaden reservoirs or tanks for holding the
heated acid; and an ammonia condenser which is a wooden chamber having its
walls lined with sheet lead. In the lower part of the said condenser is placed a
coil of pipe through which steam, and preferably the exhaust steam of an engine,
passes. This coil is connected with coils standing in both of the reservoirs or
tanks, so that the steam which heats the coil in the condenser will pass through
the coils in the tanks also.
The object of allowing the steam to pass through these coils is to keep the
solutions, or the sulphuric acid, constantly in a heated state.
The hot sulphuric acid or solution is driven out of the reservoirs or tanks
alternately (through pipes which extend to the bottom of the said tanks), by means
of a continuously working air pump, and is forced into the condenser where it
issues forth in fine powerful jets froin suitable openings in a pipe standing therein.
These fine jets of hot acid strike against the walls of the condenser with such
force that they are completely turned into spray, whereby the gases in the said
condenser are brought into such intimate contact with the acid solutions, that the
absorption of ammonia takes place.
The acid, now containing a small quantity of ammonin, collects in the lower
portion of the condenser which contains the steam coil; from thence it flows into
the second reservoir. After the first reservoir has been emptied and the second
filled, by the closing and opening of suitable stop cocks, the acid is again driven

page_text: into the condenser by the compressed air from the air-pump. In the condenser it
is again brought into immediate contact with the gases; and this treatment is
repeated until the entire quantity of acid is neutralized by the ammonia. As a
consequence, a concentrated hot solution of sulphate of ammonia is obtained, from
which, after first drawing off and cooling, crystals of sulphate of ammonia are
immediately formed.
Any lye in excess of the salt proper can be utilized for the dilution of the
concentrated sulphuric acid which is employed afresh to recharge the apparatus.
The ammoniacal gases are conveyed to the condenser in any suitable manner.
Near the point where they enter the condenser, two wire netting slides aro
arranged which are alternately removed in order to collect the sooty products of
combustion.
The gases, after parting with their ammonia, pass away upwards from the
condenser, through a pipe, into a chimney.
In the upper part of the condenser
placed a finely perforated plate of lead to
prevent the solution in the form of spray from being carried off with the waste
gases.
This process for producing ammonia can be advantageously adopted in gas
works established for illuminating purposes, in manufactories for the production
of bone-black, ammonia, and soda, and, speaking generally, in all extensive
factories.